100 deg f to deg c 
Temperature Scales
Learning Objective(s)
· State the freezing and boiling points of water on the Celsius and Fahrenheit temperature scales.
· Convert from one temperature scale to the other, using conversion formulas.
Turn on the television any morning and you will see meteorologists talking about the day’s weather forecast. In addition to telling you what the weather conditions will be like (sunny, cloudy, rainy, muggy), they also tell you the day’s forecast for high and low temperatures. A hot summer day may reach 100° in Philadelphia, while a cool spring day may have a low of 40° in Seattle.
If you have been to other countries, though, you may notice that meteorologists measure heat and cold differently outside of the United States. For example, a TV weatherman in San Diego may forecast a high of 89°, but a similar forecaster in Tijuana, Mexico—which is only 20 miles south—may look at the same weather pattern and say that the day’s high temperature is going to be 32°. What’s going on here?
The difference is that the two countries use different temperature scales. In the United States, temperatures are usually measured using the Fahrenheit scale, while most countries that use the metric system use the Celsius scale to record temperatures. Learning about the different scales—including how to convert between them—will help you figure out what the weather is going to be like, no matter which country you find yourself in.
Measuring Temperature on Two Scales
Fahrenheit and Celsius are two different scales for measuring temperature.
A thermometer measuring a temperature of 22° Celsius is shown here.
On the Celsius scale, water freezes at 0° and boils at 100°.
If the United States were to adopt the Celsius scale, forecast temperatures would rarely go below 30° or above 45°. (A temperature of 18° may be forecast for a cold winter day in Michigan, while a temperature of 43° may be predicted for a hot summer day in Arizona.)
Most office buildings maintain an indoor temperature between 18°C and 24°C to keep employees comfortable.  A thermometer measuring a temperature of 72° Fahrenheit is shown here.
On the Fahrenheit scale, water freezes at 32° and boils at 212°.
In the United States, forecast temperatures measured in Fahrenheit rarely go below 20° or above 120°. (A temperature of 0° may be forecast for a cold winter day in Michigan, while a temperature of 110° may be predicted for a hot summer day in Arizona.)
Most office buildings maintain an indoor temperature between 65°F and 75°F to keep employees comfortable.  
 Celsius  Fahrenheit 

A cook puts a thermometer into a pot of water to see how hot it is. The thermometer reads 132°, but the water is not boiling yet. Which temperature scale is the thermometer measuring?
A) Celsius
B) Fahrenheit
Show/Hide Answer A) Celsius Incorrect. On the Celsius scale, water boils at 100°, so if the water is not boiling and the measurement is over 100°, then it cannot be Celsius. The correct answer is Fahrenheit.
B) Fahrenheit Correct. Water boils at 212° on the Fahrenheit scale, so a measurement of 132° on a Fahrenheit scale is legitimate for hot (but nonboiling) water.

Converting Between the Scales
By looking at the two thermometers shown, you can make some general comparisons between the scales. For example, many people tend to be comfortable in outdoor temperatures between 50°F and 80°F (or between 10°C and 25°C). If a meteorologist predicts an average temperature of 0°C (or 32°F), then it is a safe bet that you will need a winter jacket.
Sometimes, it is necessary to convert a Celsius measurement to its exact Fahrenheit measurement or vice versa. For example, what if you want to know the temperature of your child in Fahrenheit, and the only thermometer you have measures temperature in Celsius measurement? Converting temperature between the systems is a straightforward process as long as you use the formulas provided below.
Temperature Conversion Formulas
To convert a Fahrenheit measurement to a Celsius measurement, use this formula.
_{}
To convert a Celsius measurement to a Fahrenheit measurement, use this formula.
_{}

How were these formulas developed? They came from comparing the two scales. Since the freezing point is 0° in the Celsius scale and 32° on the Fahrenheit scale, we subtract 32 when converting from Fahrenheit to Celsius, and add 32 when converting from Celsius to Fahrenheit.
There is a reason for the fractions _{} and _{}, also. There are 100 degrees between the freezing (0°) and boiling points (100°) of water on the Celsius scale and 180 degrees between the similar points (32° and 212°) on the Fahrenheit scale. Writing these two scales as a ratio, _{}, gives _{}. If you flip the ratio to be _{}, you get _{}. Notice how these fractions are used in the conversion formulas.
The example below illustrates the conversion of Celsius temperature to Fahrenheit temperature, using the boiling point of water, which is 100° C.
Example  
Problem  The boiling point of water is 100°C. What temperature does water boil at in the Fahrenheit scale?  
 _{}  A Celsius temperature is given. To convert it to the Fahrenheit scale, use the formula at the left. 
 _{}  Substitute 100 for C and multiply. 
 _{} 

 _{}  Simplify_{} by dividing numerator and denominator by 5. 
 _{} 

 _{}  Add 180 + 32. 
Answer  The boiling point of water is 212°F. 
Example  
Problem  Water freezes at 32°F. On the Celsius scale, what temperature is this?  
 _{}  A Fahrenheit temperature is given. To convert it to the Celsius scale, use the formula at the left. 
 _{}  Substitute 32 for F and subtract. 
 _{}  Any number multiplied by 0 is 0. 
 _{} 

Answer  The freezing point of water is 0°C. 
The two previous problems used the conversion formulas to verify some temperature conversions that were discussed earlier—the boiling and freezing points of water. The next example shows how these formulas can be used to solve a realworld problem using different temperature scales.
Example  
Problem  Two scientists are doing an experiment designed to identify the boiling point of an unknown liquid. One scientist gets a result of 120°C; the other gets a result of 250°F. Which temperature is higher and by how much?  
 What is the difference between 120°C and 250°F?  One temperature is given in °C, and the other is given in °F. To find the difference between them, we need to measure them on the same scale. 
 _{}  Use the conversion formula to convert 120°C to °F. (You could convert 250°F to °C instead; this is explained in the text after this example.) 
 _{} 
Substitute 120 for C. 
 _{}  Multiply. 
 _{}  Simplify _{} by dividing numerator and denominator by 5. 
 _{} 
Add 216 + 32. 
 _{}  You have found that 120°C = 248°F. 
 250°F – 248°F = 2°F  To find the difference between 248°F and 250°F, subtract. 
Answer  250°F is the higher temperature by 2°F. 
You could have converted 250°F to °C instead, and then found the difference in the two measurements. (Had you done it this way, you would have found that 250°F = 121.1°C, and that 121.1°C is 1.1°C higher than 120°C.) Whichever way you choose, it is important to compare the temperature measurements within the same scale, and to apply the conversion formulas accurately.
Tatiana is researching vacation destinations, and she sees that the average summer temperature in Barcelona, Spain is around 26°C. What is the average temperature in degrees Fahrenheit?
A) 79°F
B) 3°F
C) 45°F
D) 58°F
Show/Hide Answer A) 79°F Correct. Tatiana can find the Fahrenheit equivalent by solving the equation _{}. The result is 78.8°F, which rounds to 79°F.
B) 3°F Incorrect. You used the wrong formula. To find the Fahrenheit equivalent, use the formula _{}. The correct answer is 79°F.
C) 45°F Incorrect. You misapplied the formula; try substituting 26 for C in the formula _{}. The correct answer is 79°F.
D) 58°F Incorrect. You misapplied the formula; try substituting 26 for C in the formula _{}. The correct answer is 79°F.

Temperature is often measured in one of two scales: the Celsius scale and the Fahrenheit scale. A Celsius thermometer will measure the boiling point of water at 100° and its freezing point at 0°; a Fahrenheit thermometer will measure the same events at 212° for the boiling point of water and 32° as its freezing point. You can use conversion formulas to convert a measurement made in one scale to the other scale.
Fahrenheit to Celsius
Quick and easy Fahrenheit to Celsius conversion
There's a simple rule to convert Fahrenheit to Celsius that should be good enough for general use. Simply take 30 off the Fahrenheit value, and then half that number.
Note that this value isn’t perfect, but it might save you having to reach for a calculator (or our site!)
Absolute Zero  459.67°F  273.15°C 

Parity  40°F  40°C 
Zero  0°F  17.78°C 
Freezing point  32°F  0°C 
Body Temperature  98.6°F  37°C 
Boiling point  212°F  100°C 
Definition of Fahrenheit and Celsius
In the Fahrenheit scale, water freezes at 32 degrees, and boils at 212 degrees. Boiling and freezing point are therefore 180 degrees apart. Normal body temperature is considered to be 98.6 °F (in reallife it fluctuates around this value). Absolute zero is defined as 459.67°F.
The Celsius scale is nowadays set in such a way that Zero degrees C is the temperature at which ice melts (note : not the temperature at which it freezes, which is different!) . At the other end of the scale, 100 degrees Celsius is the boiling point of water.
The scientific definition of Celsius is now defined against degrees Kelvin. Zero degrees Celsius is 273.15K. One degree Celsius is equal to one Kelvin, so we can say that the boiling point of water is equal to 273.15 + 100 = 373.15 Kelvin.
Fahrenheit to Celsius formula
°C =
°F  32
______
1.8000
Why is converting Fahrenheit to Celsius so complicated?
Most things we measure – length, width, time etc. have one thing in common – their values all start from zero. We all know exactly how long zero centimeters or inches is, and can convert zero of any of those units into another type of unit very easily. Zero centimeters = zero meters = zero inches. Taking inches and centimeters as an example, to go from zero inches to 1 inch we need to add one inch. So far, so obvious.
Similarly, to go from zero centimeters to 1 centimeter, we need only add 1 centimeter. The only difference between adding one inch or one centimetre is the amount of distance we're adding. The relationship between an inch and a centimetre is that 1 inch is 2.54 centimetres. So we can say that adding 1 inch is the same as adding 2.54 centimetres. Because they both start at zero, the formula to convert between the two very easy (in = cm * 0.39370)
Temperature units aren't built in the same simple way, because they don't all start in the same place at zero. If we pegged absolute zero to be 0°F, 0°C and 0K, converting between them would be much easier, but Fahrenheit and Celsius were defined before we could tell where absolute zero was, and as a result Fahrenheit, Celsius and Kelvin all start from different values.
Because these temperature units don’t share a common zero point, we need to add or subtract an offset before we do our division or multiplication. It's not a difficult extra step, but it seems to be something that can cause confusion. As a rough rule of thumb:
To go from Fahrenheit to Celsius, take 30 off the Fahrenheit value, and then half that number.
For a 100% accurate answer, subtract 32 and divide by 1.8 (or use the calculator above!)
Celsius to Fahrenheit Conversion
I moved to England and the imperial measurement units and different temperature scales are a huge problem in everyday life. Temperatures for baking or cooking are mostly stated as Fahrenheit, but the temperature on the oven is stated as Celsius.
The conversion is not straightforward because both temperature scales use different fixed points and scale widths. Therefore a Celsius Fahrenheit Converter is a useful tool.
How to convert Celsius to Fahrenheit without the use of a calculator? There are some mnemonics and rules of thumb to give an approximate estimate about temperature conversion. Those who want to convert baking temperatures are lucky. The temperature can be easily doubled or divided by half. The following Celsius To Fahrenheit Conversion Table shows the temperature between 200 and 500 degrees Fahrenheit and their approximated degrees Celsius equivalent, as well as the error of the approximate conversion.
T_{F} [°F]  T_{C,estimated}[°C]  T_{C,calculated} [°C]  Error [°C] 

200  100  93  7 
220  110  104  6 
240  120  116  4 
260  130  127  3 
280  140  138  2 
300  150  149  1 
320  160  160  0 
340  170  171  1 
360  180  182  2 
380  190  193  3 
400  200  204  4 
420  210  216  6 
440  220  227  7 
460  230  238  8 
480  240  249  9 
500  250  260  10 
If you consider that baking temperatures are mostly between 150°C and 220°C, then the maximum error would only be 7 degrees centigrade. A more accurate conversion is not always necessary. For example 350 Fahrenheit equals 176.67 Celsius. If you would use the rule of thumb the error would be 1.67 degrees centigrade. This error is negligible in most circumstances.
Be aware that this rule of thumb only works with baking temperatures and does not work with lower temperatures like the ones seen on the weather forecast. Should the weather forecast predict a sunny day of 32 degrees Fahrenheit, and you expect 16 degree Celsius using this rule of thumb; then you will most certainly be freezing. This is because 32 degree Fahrenheit equals 0 degrees Celsius. However, don't be afraid as this example shows you another mnemonic. As I said, 0 degree Celsius equals 32 degrees Fahrenheit. Furthermore, 16 and 61 is a good number for the conversion of Fahrenheit to Celsius. Because 16 degree Celsius equals approximately 61 degrees Fahrenheit.
Therefore, to convert Celsius to Fahrenheit it is not always necessary to use difficult mathematics. But, if you need an accurate conversion then you can use the Celsius Fahrenheit Converter above. Just fill in your values in one of the boxes and click outside of the boxes to convert.
In addition, you can find the Fahrenheit Celsius Conversion Equations and historical information on the development of the Fahrenheit scale and Celsius scale.
This is a check card sized conversion table for cooking and baking temperatures. You can print it and pin it on your fridge.
Download Printable Conversion Table
Learning Objectives
 Define temperature.
 Describe the Fahrenheit temperature scale.
 Describe the Celsius temperature scale.
 Describe the Kelvin temperature scale.
What is temperature?
Touch the top of the stove after it has been on and it feels hot. Hold an ice cube in your hand and it feels cold. Why? The particles of matter in a hot object are moving much faster than the particles of matter in a cold object. An object’s kinetic energy is the energy due to motion. The particles of matter that make up the hot stove have a greater amount of kinetic energy than those in the ice cube.
Temperature is a measure of the average kinetic energy of the particles in matter. In everyday usage, temperature indicates a measure of how hot or cold an object is. Temperature is an important parameter in chemistry. When a substance changes from solid to liquid, it is because there was an increase in the temperature of the material. Chemical reactions usually proceed faster if the temperature is increased. Many unstable materials (such as enzymes) will be viable longer at lower temperatures.
Figure 1. The glowing charcoal on the left represents high kinetic energy, while the snow and ice on the right are of much lower kinetic energy.
Temperature Scales
Figure 2. Daniel Gabriel Fahrenheit.
The first thermometers were glass and contained alcohol, which expanded and contracted as the temperature changed. The German scientist, Daniel Gabriel Fahrenheit used mercury in the tube, an idea put forth by Ismael Boulliau. The Fahrenheit scale was first developed in 1724 and tinkered with for some time after that. The main problem with this scale is the arbitrary definitions of temperature. The freezing point of water was defined as 32°F and the boiling point as 212°F. The Fahrenheit scale is typically not used for scientific purposes.
Figure 3. Anders Celsius.
The Celsius scale of the metric system is named after Swedish astronomer Anders Celsius (1701–1744). The Celsius scale sets the freezing point and boiling point of water at 0°C and 100°C respectively. The distance between those two points is divided into 100 equal intervals, each of which is one degree. Another term sometimes used for the Celsius scale is “centigrade” because there are 100 degrees between the freezing and boiling points of water on this scale. However, the preferred term is “Celsius.”
Figure 4. Lord Kelvin.
The Kelvin temperature scale is named after Scottish physicist and mathematician Lord Kelvin (18241907). It is based on molecular motion, with the temperature of 0 K, also known as absolute zero, being the point where all molecular motion ceases. The freezing point of water on the Kelvin scale is 273.15 K, while the boiling point is 373.15 K. Notice that here is no “degree” used in the temperature designation. Unlike the Fahrenheit and Celsius scales where temperatures are referred to as “degrees F” or “degrees C,” we simply designated temperatures in the Kelvin scale as kelvins.
As can be seen by the 100 kelvin difference between the two, a change of one degree on the Celsius scale is equivalent to the change of one kelvin on the Kelvin scale. Converting from the Kelvin scale to the Celsius scale or vice versa is easy, as you simply add or subtract 273.
Figure 5. Comparing the three different temperature scales.
Converting between the Celsius and Fahrenheit temperature scales is a little bit trickier but still not too difficult. To convert from Fahrenheit to Celsius, first multiply the temperature in Celsius (T_{C}) by 1.8 and then add 32, in that order.
[latex]\text{T}_{\text{F}}=1.8\times\text{T}_{\text{C}}+32[/latex]
To convert from Celsius to Fahrenheit, first subtract 32 from the temperature in Fahrenheit then divide by 1.8, in that order.
[latex]\displaystyle\text{T}_{\text{C}}=\frac{\text{T}_{\text{F}}32}{1.8}[/latex]
Summary
 Temperature is a measure of the average kinetic energy of the particles in matter.
 The Fahrenheit scale defines the freezing point of water as 32°F and the boiling point as 212°F.
 The Celsius scale sets the freezing point and boiling point of water at 0°C and 100°C respectively.
 The Kelvin scale is based on molecular motion, with the temperature of 0 K, also known as absolute zero, being the point where all molecular motion ceases.
Practice
Use the link below to answer the following questions:
http://www.visionlearning.com/library/module_viewer.php?mid=48
 What mixture did Fahrenheit use to set his thermometer at zero degrees?
 Why is the Celsius scale preferred in scientific work over the Fahrenheit scale?
 What was the idea behind the establishment of the Kelvin temperature scale?
 What is the advantage of using the Kelvin scale at low temperatures?
Review
 What is absolute zero on the Celsius temperature scale?
 What are the freezing and boiling points of water in the Celsius scale?
 Convert the following Kelvin temperatures to degrees Celsius.
 188 K
 631 K
 Temperature in degrees Fahrenheit can be converted to Celsius by first subtracting 32, then dividing by 1.8. What is the Celsius temperature outside on a warm day (88°F)?
 Why is the Celsius scale sometimes called “centigrade”?
Glossary
Temperature Converter: Fahrenheit to Celsius & More
Fahrenheit and celsius temperature conversion
Converting from Fahrenheit to Celsius
From the mid18th to mid20th centuries, Fahrenheit was the system most widely used in Englishspeaking countries, while continental Europeans preferred 'The Swedish Scale'. With the drive to standardisation and metrication from the 1950s, Celsius became the adopted temperature scale for the EEC (later EU), with the UK and Ireland converting (somewhat reluctantly) after joining the European community.
This reluctance was partly due to human preference. For while the Celsius scale was developed for convenience, Fahrenheit's scale was based on observation and measurement. Also, whereas Fahrenheit had developed a ratio scale, Celsius had produced an interval scale. These are very different things, as we shall explain in a future article.
This may help explain why many people prefer Fahrenheit readings as rather closer to actual experience. In Celsius, a chilly day at 11°C does not seem greatly different from a really hot one at 35°C. On the Fahrenheit scale, these respectively measure at about 52°F and 95°F, with the latter traditionally taken as license for red top tabloids to start running 48 point headlines containing words like 'Phew', 'Flaming' and 'Scorcher'.
Incidentally, while the UK's Met Office started publishing temperatures in both Celsius and Fahrenheit from 1962 and dropping use of Fahrenheit altogether from official reports in 1970, British media persisted in using Fahrenheit in weather reports well into the 21st century. Indeed it became the fashion to use Celsius when describing extreme winter conditions and Fahrenheit for heat waves  a nice example of double standards in action.
Fahrenheit and Celsius formula
The formula to convert Fahrenheit to Celsius is:
[°C] = ([°F]  32) × 5/9
In other words, take your Fahrenheit reading, subtract 32, multiply the answer by five and then divide by nine. So 66 degrees Fahrenheit minus 32 would be 34, times five makes 170 divided by nine equals 18.88 recurring, or 18.9°C.
Celsius and Fahrenheit formula
[°F] = [°C] × 9/5 + 32
Here, you multiply your Celsius temperature by nine, divide by five and then add 32 to find the Fahrenheit reading.
So, 13 degrees Celsius times nine is 117, divided by five is 23.4, plus 32 makes 55.4°F.
Using decimals
To make life a little simpler, using decimals instead of fractions, you can use 1.8 instead of 9/5.
This gives the following modified formulae
 Celsius to Fahrenheit:
(°C + 40) × 1.8  40 = °F  Fahrenheit to Celsius:
(°F + 40) / 1.8  40 = °C
Trying this out in action on a hot day (and remembering that multiplying by 1.8 is the same as doubling and then subtracting 10 per cent) we could have 36°C plus 40 is 76, times 1.8 is 136.8 minus 40 is 96.8°F, which is firmly in 'Scorcha' territory.
And the other way, on a rather chillier day, 48°F plus 40 is 88, divided by 1.8 is 48.88 recurring (48.9) minus 40 equals 8.9°C, which actually does sound quite cold.
Fahrenheit to Celsius reference chart
Celsius readings rounded up or down to single decimal points.
Celsius to Fahrenheit reference chart
Fahrenheit readings rounded up or down to nearest whole degree
Conversion units for the Temperature Converter
Celsius or Centigrade, Fahrenheit, Kelvin, Rankine, Reamur,
If you are cooking or baking, take a look at our charts for oven temperature conversions.
To help with productivity, we now set a cookie to store the last units you have converted from and to. This means that when you revisit this temperature converter, the units will automatically be selected for you.
What Is the Degree Difference Between Celsius vs. Fahrenheit?
The Fahrenheit and Celsius scales are the two most common temperature scales. However, the two scales use different measurements for the freezing and boiling points of water, and also use different sized degrees. To convert between Celsius and Fahrenheit you use a simple formula that takes this difference into account.
Boiling/Freezing Point and Degree Size
Fahrenheit and Celsius both use different temperatures for the freezing and boiling points of water, and also use differently sized degrees. Water freezes at 0 degrees Celsius, and boils at 100 degrees C, while in Fahrenheit, water freezes at 32 degrees F and boils at 212 degrees F. You see that Celsius has 100 degrees between the freezing and boiling point, whereas Fahrenheit has 180 degrees between these two points. One degree Celsius is 1.8 times larger than one degree Fahrenheit.
Degree Conversion
Use the relationship in degree size to convert between Celsius and Fahrenheit. Because Celsius degrees are larger than those in Fahrenheit, to convert from Celsius to Fahrenheit, multiply the Celsius temperature by 1.8, then add 32. Convert from Celsius to Fahrenheit using the following equation:
You can also use this formula to convert from Fahrenheit to Celsius. To convert the Fahrenheit temperature, first subtract 32, then divide the result by 1.8.
Based on these equations, you can find a temperature where Celsius and Fahrenheit are the same  at minus 40.
References
About the Author
Jon Zamboni began writing professionally in 2010. He has previously written for The Spiritual Herald, an urban health care and religious issues newspaper based in New York City, and online music magazine eBurban. Zamboni has a Bachelor of Arts in religious studies from Wesleyan University.
Celsius to Fahrenheit (°C to °F)
Simple, quick °C to °F conversion
Celsius to Fahrenheit conversion is probably the most confusing conversion there is, but a simple °C to °F conversion is actually quite easy – just double the °C figure and add 30. This should be reasonably accurate for weather temperatures.
Absolute Zero  273.15°C  459.67°F 

Parity  40.00°C  40°F 
Freezing point  0°C  32°F 
Body Temperature  37°C  98.6°F 
Boiling point  100°C  212°F 
Celsius and Fahrenheit definition
The Celsius temperature range was originally defined by setting zero as the temperature at which water froze. Zero degrees C was later redefined as the temperature at which ice melts. The other point at which Celsius was set – 100 degrees Celsius – was defined as the boiling point of water.
Since its definition, the Celsius scale has been redefined to peg it to Kelvin. Zero degrees Celsius is now defined as 273.15K. As one degree Celsius is equal to one Kelvin, boiling point of water is equal to 273.15 + 100 = 373.15 Kelvin.
The Fahrenheit temperature range is based on setting the freezing point of water at 32 degrees, and boiling to 212 degrees. This means that boiling and freezing point are 180 degrees apart. Absolute zero is defined as 459.67°F.
Celsius to Fahrenheit formula
°F =
°C * 1.8000
+ 32.00
Why is converting Celsius to Fahrenheit so difficult?
Because both Celsius and Fahrenheit scales are offset– ie neither are defined as starting at zero. On top of that, for every additional unit of heat energy the Celsius and Fahrenheit scales add a different additional value. Because of this setup, it’s impossible to say that doubling the °C or °F value doubles the amount of heat energy, so it’s difficult to get an intuitive grasp of how much energy 1 degree Fahrenheit or Celsius actually is.
The only temperature system that works intuitively – where a doubling of value doubles the energy – is Kelvin, where absolute zero is 0, body temperature is 310.15K and boiling water is 373.15K. The problem with the Kelvin scale is that the zero end of the scale is too far from human experience to be useful – as anyone who set their room temperature to 20.5 Kelvin would attest, if they lived long enough.
What is the difference between Centigrade and Celsius?
It’s just a naming convention. Degrees Centigrade and degrees Celsius are the same thing. Degrees Celsius (invented by Anders Celsius) are sometimes called Centigrade, because the scale was defined between 0 and 100 degrees, hence centigrade meaning a scale consisting of 1/100ths.
Common conversions from Celsius to Fahrenheit
 25°C= 77°F
 30°C= 86°F
 33°C= 91.4°F
 35°C= 95°F
 40°C= 104°F
 180°C= 356°F
Common misspellings of Celsius
Common misspellings of Fahrenheit
 Farenheit
 Farenheight
 Ferenheit
 Ferenheight
 Ferinheit
 Ferinheight
 Fahrinheight
 Fahenhiet
Degree Symbol
°
Degree symbol is °. Sometimes students or those who deal with mathematics, physics or various kinds of calculations may need to type a degree sign, but we do not have one directly on our keyboard. Degree symbol can be used in case if we're dealing with angles, or when we need to operate with temperature and use Celsius degree. It is also a common coordinate degree sign. Actually, there are a few ways to make a degree symbol. You can either copy paste, or use the degree code in your document. See some examples below:
html degree decimal
html degree hex
html degree named
How to Type Degree Symbol on Microsoft Windows PC?
Press and hold the key and type on the numeric keypad of your keyboard. Make sure the Home savings and loan credit card is on and type 0176 with the leading zero. If there is no numeric keypad, press and hold the before typing the 0176 numbers of degree symbol.
How to Type Degree Symbol on Mac OS?
Press and hold the keys on your keyboard.
Degree Symbol in LaTeX
Degree symbol can be typed in LaTeX with using packages.
Celsius Degree Symbol
celsius degree decimal
celsius degree hex
celsius degree source code
Fahrenheit Degree Symbol
fahrenheit degree decimal
fahrenheit degree hex
fahrenheit degree source code
Masculine Ordinal Indicator Symbol
degree decimal
degree hex
degree source code
Ring Above Symbol
degree decimal
degree hex
degree source code
Ring Below Symbol
degree decimal
degree hex
degree source code
Superscript Zero Symbol
degree decimal
degree hex
degree source code
Ring Operator Symbol
degree decimal
degree hex
degree source code
Degree Symbol Examples
Degree symbol in geometry.
 Right angle is 90°. (90 degrees)
 Straight angle is 180°. (180 degrees)
 Acute angle is less than 90°. (<90 degrees)
 Obtuse angle is greater than 90° and less than 90°. (>90 degrees and <180 degrees)
 Reflex angle is greater than 180°. (>180 degrees)
Degree symbol in geographic coordinate system.
 Latitude 32.344790 is equal to 32° 20' 41.244'' N. (32 degrees North)
 Longitude 64.692307 is equal to 64°° 41' 32.3052'' W. (64 degrees West)
Degree symbol in temperature measurements.
 2°C : 2 degrees Celsius
 20°C : 20 degrees Celsius
 23°C : 23 degrees Celsius
 10℃ : 10 degrees Celsius
 15℃ : 15 degrees Celsius
 21℃ : 21 degrees Celsius
Copy Paste Degree Symbol
°
Also check out the other usages of degree symbol:
Helpful Resources
What is temperature? Facts about Fahrenheit, Celsius and Kelvin scales
Hot and cold are measured using a numeric scale called temperature. Temperature scales are how we communicate about the weather, measure safety and comfort and explain the physical world. Using baselines chosen by scientists to create relative measurements, temperature scales measure heat intensity, or the amount of thermal energy contained in a material or substance (like the air, a pot of water or the surface of the sun). There are three commonly used measurement systems: Fahrenheit, Celsius and Kelvin.
What is temperature?
Temperature is energy measured with a tool called a thermometer, which comes from the Greek words "thermos" (hot) and "metron" (measure), according to the Online Etymology Dictionary. Another definition of temperature is that it's a measure of the average kinetic energy — the energy of a mass in motion — of a substance's molecules, according to Georgia State University
The ancient Greek physician Hippocrates allegedly taught that the human hand could be used to judge the presence of fever in a person as early as 400 B.C., according to a 2019 report in the journal Nature Public Health Emergency Collection. However, precise instruments to measure human body temperature were not developed until the sixteenth and seventeenth centuries.
Fahrenheit: The first precise thermometer
In 1714, the Polishborn Dutch physicist, inventor and scientific instrument maker Daniel Gabriel Fahrenheit unveiled a mercurybased thermometer. Mercury, a liquid metal, expands and contracts based on the surrounding temperature When Fahrenheit placed mercury in a closed tube marked with a numbered scale, he saw the mercury rise and fall when it was exposed to different temperatures. According to The Royal Society in the United Kingdom, this was the world's first known practical, accurate thermometer.
Fahrenheit had based his invention on Danish scientist Ole Roemer's alcoholbased thermometer. Roemer labeled his temperature scale with zero marked at the temperature where brine (salt water) froze and 60 as the point at which water boiled, wrote Ulrich Grigull, the late director of the Institute for Thermodynamics at the Technical University of Munich in Germany, in a 1986 conference presentation. Ice melted at 7.5 degrees on the Roemer scale, and a human body registered at 22.5.
Related: What if temperature determined a baby's sex?
Fahrenheit's thermometer, though, was much more accurate. He used the same freezing and boiling reference points as Roemer's scale — referred to in his writings as "Extream Cold" and "Extream Hott" — but roughly multiplied the scale by four to divide each marker on the scale into finer increments. On Fahrenheit's scale, wrote Grigull, the four reference points were: 0 (at the combined freezing temperature of brine), 30 (the freezing point of regular water), 90 (body temperature) and 240 (the boiling point of water).
Related: Supernovas heat atoms to hundreds of millions of degrees Fahrenheit.
Fahrenheit published a paper describing his scale in the journal Philosophical Transactions in 1724. That same year, Fahrenheit was inducted into the Royal Society, the United Kingdom’s national science academy. Grigull wrote "His fellowship of the Royal Society resulted in his thermometer, and thereby his scale, receiving particular acceptance in England and consequently later also in North America and the British Empire." Fahrenheit's measurement system, sometimes referred to as part of the imperial system, traveled the world with the British Empire.
Related: The world's oceans are heating up at an accelerated rate.
However, only a few countries today still use Fahrenheit to measure temperature. The United States and its territories, along with the Bahamas, Palau, Belize, the Cayman Islands, the Federated States of Micronesia and the Marshall Islands, have stuck with the temperature scale, despite the rest of the world moving to the Celsius scale, according to the online geography resource World Atlas.
After Fahrenheit's death in 1736, the Fahrenheit scale was recalibrated to make it slightly more accurate. The exact freezing and boiling points of plain water, minus the salt, were marked at 32 and 212 degrees Fahrenheit, respectively. Normal human body temperature 100 deg f to deg c marked at 98.6.
Read more: Has the average human body bb&t and wells fargo changed?
Temperatures in Fahrenheit are often expressed as a number followed by ℉, or simply F.
Celsius: A more scientific scale
"Anders Celsius should be recognized as the first to perform and publish careful experiments aiming at the definition of an international temperature scale on scientific grounds," wrote Olof Beckman, a solid state physicist at Uppsala University in Sweden. Celsius was a Swedish astronomer and is credited with discovering the connection between the aurora borealis, also known as the Northern Lights, and the Earth's magnetic field, as well as a method for determining the brightness of stars, according to the U.S. National High Magnetic Field Laboratory.
In a proposal to the Royal Swedish Academy of Sciences in 1742, Celsius proposed a scale based on two fixed points: 0 (the boiling point of water) and 100 (the freezing point of water). Following Celsius' death in 1744, the famous Swedish taxonomist Carl Linnaeus proposed that the fixed points be switched, with 0 indicating the freezing point of water and 100 its boiling point, according to The Legacy of Anders Celsius in JSTOR Daily, a digital library. The scale has also been extended to include negative numbers.
Celsius initially called his scale "Centigrade" from the Latin for one hundred ("centi") degrees ("grade"), because there were 100 points between water freezing and boiling. In 1948, an international conference on weights and measures (Conference General des Poids et Measures) changed the name to "Celsius" in honor of Anders Celsius, according to the U.S. National Institute of Standards and Technology (NIST).
Related: As the 2015 Paris Agreement aims to cut emissions, we have already blown past warming targets.
The Celsius scale is part of the metric system, otherwise known as the International System of Units (SI). Temperatures in Celsius can be expressed as a number of degrees followed by the symbols ℃, or simply C.
The Celsius scale has 100 degrees between water boiling and freezing, while Fahrenheit has 180 degrees. This means that a single degree Celsius equals 1.8 degrees Fahrenheit. At 40°, both scales have the same value: 40 C = 40 F.
Kelvin: An absolute scale for scientists
In 1848, British mathematician and scientist William Thomson (also known as Lord Kelvin) proposed an absolute temperature scale, which was independent of the properties of a substance like ice or the human body. He suggested that the range of possible temperatures in the universe far exceeded those proposed by Celsius and Fahrenheit. The concept of an absolute minimum temperature was not new, according to NIST, but Kelvin put an exact number to it: 0 kelvins is equal to 273.15 C.
Related: What's the coldest place in the universe?
"Thermodynamic temperature" is distinct from temperatures based on freezing and melting points of fluids, Julia Scherschligt, an expert in vacuum and pressure metrology at the National Institute of Science and Technology in the United States, told Live Science.
"Thermodynamic temperature is absolute, not relative to fixed points. It describes the amount of kinetic energy contained by the particles that constitute a blob of matter, that wiggle and jiggle around at submicroscopic levels," she said. "As the temperature drops, the particles slow down until at some point, all motion ceases. This is crbauto online payment zero, which is the benchmark of the Kelvin scale."
Related: Scientists pinpoint a new record for coldest natural temperature in Greenland.
Absolute zero occurs at −273.15 C or −459.67 F. Until recently, scientists thought that humans could not recreate this temperature (because to become that cold, energy would have to 100 deg f to deg c added to the system to cool it, meaning that the system would be warmer than absolute zero). But in 2013, German physicists managed to push particles into paradoxical temperatures below absolute zero.
To Kelvin's mind, absolute zero was where a temperature scale should begin, but for convenience, he used the markers and intervals of the widelyknown Celsius scale as a base for his own. As such, in the Kelvin scale, water freezes at 273.15 K (0 C) and boils at 373.15 K, or 100 C.
A single kelvin is referred to as a unit, rather than a degree, and is equal to a single degree on the Celsius scale. The Kelvin scale is mainly used by scientists.
In 2018, the Kelvin was redefined to make it more accurate, according to a paper in the journal Metrologia, and its definition is now tethered to the Boltzmann constant. This constant links temperature to the kinetic energy inside matter.
The new definition, according to the General Conference on Weights and Measures, is: "The kelvin, symbol K, is the SI unit of thermodynamic temperature; its magnitude is set by fixing the numerical value of the Boltzmann constant to be equal to exactly 1.380649 × 1023.J K1 [joules per kelvin]."
Which scale is best?
The best scale for measuring temperatures can vary depending on the circumstance, namely the community with whom you are sharing information. Historically, Americans use the Fahrenheit scale for daily life, including for weather and cooking, so it is best to use Fahrenheit measurements in the United States. But most countries use Celsius, so it is better to use that scale across the rest of the globe, and while communicating internationally. Ultimately, the best scale for casual use depends on convention and what people around you are using.
But which scale is the most precise?
"Precision isn't really a feature of a scale," Scherschligt said. Rather, the precision of a measurement depends on the increments given by the thermometer being used, and the technique of the person using it. "A number can be measured with arbitrary precision on any scale. But only the kelvin is physicsbased, which means it is the most accurate scale."
The Kelvin scale, which is based on the physical properties of any gas, can be calibrated precisely anywhere in the universe with proper equipment and a universal constant. That’s why scientists often prefer to use the Kelvin scale in their experiments.
Conversion formulas
Celsius to Fahrenheit: Multiply by 9, divide by 5, then add 32
Fahrenheit to Celsius: Subtract 32, then multiply by 5, then divide by 9
Celsius to Kelvin: Add 273
Kelvin to Celsius: Subtract 273
Fahrenheit to Kelvin: Subtract 32, multiply by 5, divide by 9, and then add 273.15
Kelvin to Fahrenheit: Subtract 273.15, multiply by 1.8, and then add 32
Additional resources
 Here is a video on how to make a thermometer at home.
 This video compares the coldest temperatures known to humans with the hottest.
 Meet the universal constants that define the International System of Units, also known as the metric system.
Celsius to Fahrenheit (°C to °F)
Simple, quick °C to °F conversion
Celsius to Fahrenheit conversion is probably the most confusing conversion there is, but a simple °C to °F conversion is actually quite easy – just double the °C figure and add 30. This should be reasonably accurate for weather temperatures.
Absolute Zero  273.15°C  459.67°F 

Parity  40.00°C  40°F 
Freezing point  0°C  32°F 
Body Temperature  37°C  98.6°F 
Boiling point  100°C  212°F 
Celsius and Fahrenheit definition
The Celsius temperature range was originally defined by setting zero as the temperature at which water froze. Zero degrees C was later redefined as the temperature at which ice melts. The other point at which Celsius was set – 100 degrees Celsius – was defined as the boiling point of water.
Since its definition, the Celsius scale has been redefined to peg it to Kelvin. Zero degrees Celsius is now defined as 273.15K. As one degree Celsius is equal to one Kelvin, boiling point of water is equal to 273.15 + 100 = 373.15 Kelvin.
The Fahrenheit temperature range is based on setting the freezing point of water at 32 degrees, and boiling to 212 degrees. This means that boiling and freezing point are 180 degrees apart. Absolute zero is defined as 459.67°F.
Celsius to Fahrenheit formula
°F =
°C * 1.8000
+ 32.00
Why is converting Celsius to Fahrenheit so difficult?
Because both Celsius and Fahrenheit scales are offset– ie neither are defined as starting at zero. On top of that, for every additional unit of heat energy the Celsius and Fahrenheit scales add a different additional value. Because of this setup, it’s impossible to say that doubling the °C or °F value doubles the amount 100 deg f to deg c heat energy, so it’s difficult to get an intuitive grasp of how much energy 1 degree Fahrenheit or Celsius actually is.
The only temperature system that works intuitively – where a doubling of value doubles the energy – is Kelvin, where absolute zero is 0, body temperature is 310.15K and boiling water is 373.15K. The problem with the Kelvin scale is that the zero end of the scale is too far from human experience to be useful – as anyone who set their room temperature to 20.5 Kelvin would attest, if they lived long enough.
What is the difference between Centigrade and Celsius?
It’s just a naming convention. Degrees Centigrade and degrees Celsius are the same thing. Degrees Celsius (invented by Anders Celsius) are sometimes called Centigrade, because the scale was defined between 0 and 100 degrees, hence centigrade meaning a scale consisting of 1/100ths.
Common conversions from Celsius to Fahrenheit
 25°C= 77°F
 30°C= 86°F
 33°C= 91.4°F
 35°C= 95°F
 40°C= 104°F
 180°C= 356°F
Common misspellings of Celsius
Common misspellings of Fahrenheit
 Farenheit
 Farenheight
 Ferenheit
 Ferenheight
 Ferinheit
 Ferinheight
 Fahrinheight
 Fahenhiet
Learning Objectives
 Define temperature.
 Describe the Fahrenheit temperature scale.
 Describe the Celsius temperature scale.
 Describe the Kelvin temperature scale.
What is temperature?
Touch the top of the stove after it has been on and it feels hot. Hold an ice cube in your hand and it feels cold. Why? The particles of matter in a hot object are moving much faster than the particles of matter in a cold object. An object’s kinetic energy is the energy due to motion. The particles of matter that make up the hot stove have a greater amount of kinetic energy than those in the ice cube.
Temperature is a measure of the average kinetic energy of the particles in matter. In everyday usage, temperature indicates a measure of how hot or cold an object is. Temperature is an important parameter in chemistry. When a substance changes from solid to liquid, it is because there was an increase in the temperature of the material. Chemical reactions usually proceed faster if the temperature is increased. Many unstable materials (such as enzymes) will be viable longer at lower temperatures.
Figure 1. The glowing charcoal on the left represents high kinetic energy, while the snow and ice on the right are of much lower kinetic energy.
Temperature Scales
Figure 2. Daniel Gabriel Fahrenheit.
The first thermometers were glass and contained alcohol, which expanded and contracted as the temperature changed. The German scientist, Daniel Gabriel Fahrenheit used mercury in the tube, an idea put forth by Ismael Boulliau. The Fahrenheit scale was first developed in 1724 and tinkered with for some time after that. The main problem with this scale is the arbitrary definitions of temperature. The freezing point of water was defined as 32°F and the boiling point as 212°F. The Fahrenheit scale is typically not used for scientific purposes.
Figure 3. Anders Celsius.
The Celsius scale of the metric system is named after Swedish astronomer Anders Celsius (1701–1744). The Celsius scale sets the freezing point and boiling point of water at 0°C and 100°C respectively. The distance between those two points is divided into 100 equal intervals, each of which is one degree. Another term sometimes used for the Celsius scale is “centigrade” because there are 100 degrees between the freezing and boiling points of water on this scale. However, the preferred term is “Celsius.”
Figure 4. Lord Kelvin.
The Kelvin temperature scale is named after Scottish physicist and mathematician Lord Kelvin (18241907). It is based on molecular motion, with the temperature of 0 K, also known as absolute zero, being the point where all molecular motion ceases. The freezing point of water on the Kelvin scale is 273.15 K, while the boiling point is 373.15 K. Notice that here is no “degree” used in the temperature designation. Unlike the Fahrenheit and Celsius scales where temperatures are referred to as “degrees F” or “degrees C,” we simply designated temperatures in the Kelvin scale as kelvins.
As can be seen by the 100 kelvin difference between the two, a change of one degree on the Celsius scale is equivalent to the change of one kelvin on the Kelvin scale. Converting from the Kelvin scale to the Celsius scale or vice versa 100 deg f to deg c easy, as you simply add or subtract 273.
Figure 5. Comparing the three different temperature scales.
Converting between the Celsius and Fahrenheit temperature scales is a little bit trickier but still not too difficult. To convert from Fahrenheit to Celsius, first multiply the temperature in Celsius (T_{C}) by 1.8 and then add 32, in that order.
[latex]\text{T}_{\text{F}}=1.8\times\text{T}_{\text{C}}+32[/latex]
To convert from Celsius to Fahrenheit, first subtract 32 from the temperature in Fahrenheit then divide by 1.8, in that order.
[latex]\displaystyle\text{T}_{\text{C}}=\frac{\text{T}_{\text{F}}32}{1.8}[/latex]
Summary
 Temperature is a measure of the average kinetic energy of the particles in matter.
 The Fahrenheit scale defines the freezing point of water as 32°F and the boiling point as 212°F.
 The Celsius scale sets the freezing point and boiling point of water at 0°C and 100°C respectively.
 The Kelvin scale is based on molecular motion, with the temperature of 0 K, also known as absolute zero, being the point where all molecular motion ceases.
Practice
Use the link below to answer the following questions:
http://www.visionlearning.com/library/module_viewer.php?mid=48
 What mixture did Fahrenheit use to set his thermometer at zero degrees?
 Why is the Celsius scale preferred in scientific work over the Fahrenheit scale?
 What was the idea behind the tri city bank of the Kelvin temperature scale?
 What is the advantage of using the Kelvin scale at low temperatures?
Review
 What is absolute zero on the Celsius temperature scale?
 What are the freezing and boiling points of water in the Celsius scale?
 Convert the following Kelvin temperatures to degrees Celsius.
 188 K
 631 K
 Temperature in degrees Fahrenheit can be converted to Celsius by first subtracting 32, then dividing by 1.8. What is the Celsius temperature outside on a warm day (88°F)?
 Why is the Celsius scale sometimes called “centigrade”?
Glossary
Celsius to Fahrenheit Conversion
I moved to England and the imperial measurement units and different temperature scales are a huge problem in everyday life. Temperatures for baking or cooking are mostly stated as Fahrenheit, but the temperature on the oven is stated as Celsius.
The conversion is not straightforward because both temperature scales use different fixed points and scale widths. Therefore a Celsius Fahrenheit Converter is a useful tool.
How to convert Celsius to Fahrenheit without the use of a calculator? There are some mnemonics and rules of thumb to give an approximate estimate about temperature conversion. Those who want to convert baking temperatures are lucky. The temperature can be easily doubled or divided by half. The following Celsius To Fahrenheit Conversion Table shows the temperature between 200 and 500 degrees Fahrenheit and their approximated degrees Celsius equivalent, as well as the error of the approximate conversion.
T_{F} [°F]  T_{C,estimated}[°C]  T_{C,calculated} [°C]  Error [°C] 

200  100  93  7 
220  110  104  6 
240  120  116  4 
260  130  127  3 
280  140  138  2 
300  150  149  1 
320  160  160  0 
340  170  171  1 
360  180  182  2 
380  190  193  3 
400  200  204  4 
420  210  216  6 
440  220  227  7 
460  230  238  8 
480  240  249  9 
500  250  260  10 
If you consider that baking temperatures are mostly between 150°C and 220°C, then the maximum error would only be 7 degrees centigrade. A more accurate conversion is not always necessary. For example 350 Fahrenheit equals 176.67 Celsius. If you would use the rule of thumb the error would be 1.67 degrees centigrade. This error is negligible in most circumstances.
Be aware that this rule of thumb only works with baking temperatures and does not work with lower temperatures like the ones seen on the weather forecast. Should the weather forecast predict a sunny day of 32 degrees Fahrenheit, and you expect 16 degree Celsius using this rule of thumb; then you will most certainly be freezing. This is because 32 degree Fahrenheit equals 0 degrees Celsius. However, don't be afraid as this example shows you another mnemonic. As I said, 0 degree Celsius equals 32 degrees Fahrenheit. Furthermore, 16 and 61 is a good number for the conversion of Fahrenheit to Celsius. Because 16 degree Celsius equals approximately 61 degrees Fahrenheit.
Therefore, to convert Celsius to Fahrenheit it is not always necessary to use difficult mathematics. But, if you need an accurate conversion then you can use the Celsius Fahrenheit Converter above. Just fill in your values in one of the boxes and click outside of the boxes to convert.
In addition, you can find the Fahrenheit Celsius Conversion Equations and historical information on the development of the Fahrenheit scale and Celsius scale.
This is a check card sized conversion table for cooking and baking temperatures. You can print it and pin it on your fridge.
Download Printable Conversion Table
What's the Easiest Way to Convert Fahrenheit to Celsius?
What's the difference between Celsius and Fahrenheit? It's really a quirk of history and a simple mathematical conversion. Learn the easiest way to convert Fahrenheit to Celsius as well as the reverse calculation with simple equations and a chart.
Converting Fahrenheit to Celsius
Some would consider a quick estimate the easiest way to convert a Fahrenheit temperature to a Celsius temperature. Others want a more precise answer quickly. Here, you can learn both methods.
Fahrenheit to Celsius Estimate Formula
Use this formula to get a good estimate of the Celsius temperature when converting from Fahrenheit. In this case / means divided by or to use division.
(Fahrenheit temp. [F]30)/2 = Celsius temp.
In other words, if you’d like to convert a Fahrenheit temperature to an approximate Celsius temperature:
 Start with the temperature in Fahrenheit (e.g., 100 degrees).
 Subtract 30 from this figure (e.g., 100  30 = 70).
 Divide your answer by 2 (e.g., 70 / 2 = 35).
Fahrenheit to Celsius Exact Formula
If you want a more precise calculation, you can use the more exact formula. Using this calculation, we determine that 100 degrees Fahrenheit is equivalent to 37.78 degrees Celsius.
(F  32) / 1.8 = C
In other words, if you'd like to convert a temperature reading in Fahrenheit to Celsius:
 Start with the temperature in Fahrenheit (e.g., 100 degrees).
 Subtract 32 online stock trading rankings this figure (e.g., 100  32 = 68).
 Divide your answer by 1.8 (e.g., 68 / 1.8 = 37.78)
Converting Celsius to Fahrenheit
To convert Celsius to Fahrenheit, simply reverse the equation. In this case * means times, or to use multiplication.
(C * 1.8) + 32 = F
You can use this equation to show that 100 degrees Celsius is equal to 212 degrees Fahrenheit.
 Start with the temperature in Celsius (e.g., 100 degrees).
 Multiply this figure by 1.8 (e.g., 100 * 1.8 = 180).
 Add 32 to this figure (e.g., 180 + 32 = 212).
Fahrenheit to Celsius Conversion Chart
If you really want an easy way to convert temperatures, you can use this Fahrenheit to Celsius conversion chart where the math has already been done for you.
View & Download PDF
What's the Difference Between Fahrenheit and Celsius?
If you're from the United States, you're probably accustomed to describing temperature by Fahrenheit. A very hot summer day is 100 degrees, a pleasant spring morning is 50 degrees, and 0 degrees is ungodly cold. If you're from almost anywhere else, you likely favor Celsius, where 100 deg f to deg c degrees is only pretty cold, 50 degrees is unspeakably hot, and 100 degrees happens on a stove, not outside.
Are Fahrenheit and Celsius Readings Ever the Same?
If you were wondering if there is a temperature where Fahrenheit and Celsius are the same, it's at 40 below zero, also known as 40 or negative 40. At all other temperatures, the difference is history.
History of Fahrenheit and Celsius Scales
Globally, the standard scale for everyday use is Celsius. Only the United States, islands freely associated with the US (Palau, the Marshall Islands and Micronesia), the Bahamas, the Caymans, and Liberia use Fahrenheit as their primary temperature measurement. Everybody else goes with Celsius.
History of the Fahrenheit Scale
The Fahrenheit scale was created by Daniel Gabriel Fahrenheit in 1724. Fahrenheit invented his scale for use best car rental insurance usa mercury thermometers, which he also invented. The Fahrenheit scale is a bit older than the Celsius scale.
History of the Celsius Scale
The Celsius scale was created by Anders Celsius in 1745, a couple decades after Fahrenheit. Curiously, Celsius created the reverse of the modern scale, treating 0 as the boiling point of water and 100 as the freezing point of water. Other scientists, notably Carl Linnaeus, flipped it later that year, making 0 the freezing point and 100 the boiling point of water.
Since it was originally built as a scale between 0 and 100, Celsius is also called centigrade. The word "centigrade" literally describes something that consists of or is divided into 100 degrees. That said, Celsius has been the preferred nomenclature since 1948.
The Kelvin Temperature Unit
You may have heard of temperature being measured according to kelvin. Indeed, if you're involved in the sciences, you probably use kelvin. Kelvin is a bit different than Fahrenheit and Celsius. Celsius and Fahrenheit are 100 deg f to deg c temperature scales, measuring temperatures in degrees.
History of the Kelvin Unit
Named after Lord Kelvin, a kelvin is a standard scientific unit, like a kilogram for weight or a meter for distance. The proper way to use the word, then, is not "100 degrees Kelvin" but "100 kelvin." (Note the lower case "k" in kelvin.)
1 kelvin equals 1/273.16th of the triple point of water: that is, the point at which liquid water, water vapor and solid ice can coexist. In other words, 273.16 kelvin is the exact triple point of water.
The Importance of Kelvin
The importance of kelvin is that it measures absolute temperature: absolute zero is 0 kelvin, the temperature at which all atomic motion (which creates heat) stops. There is no thermal energy whatsoever pay kohls bill in store absolute zero.
Kelvin Conversion Formulas
Kelvin is primarily of value to scientists, since it simplifies calculation at extreme temperatures. For your convenience, the conversion equations follow.
 To convert: Celsius to kelvin: C + 273.15 = K.
To convert Fahrenheit to kelvin: [(F  32) / 1.8] + 273.15 = K
You convert Celsius to Kelvin by simply adding 273.15. If the outside temperature is 10 degrees Celsius, then it is 283.15 kelvin. That's easy enough.
Fahrenheit is a bit trickier. Take your degrees Fahrenheit, subtract 32, divide by 1.8, and finally add 273.15. Here's a quick example:
 Say it is 100 degrees Fahrenheit outside.
 Subtract 32 from 100 to get 68.
 Divide 68 by 1.8 to get 37.78.
 Add 273.15 to 100 deg f to deg c 310.93. Thus, 100 degrees Fahrenheit is equal to 310.93 kelvin.
Taking Temperatures
Temperature is important! Measuring heat accurately matters in every field of human endeavor, from engineering to medicine. For more on how to manage your temperature, take a look at this automatic Celsius to Fahrenheit converter. It'll make short work of all your temperature conversions.
Michele Meleen
Staff Editor
Temperature Converter: Fahrenheit to Celsius & More
Fahrenheit and celsius temperature conversion
Converting from Fahrenheit to Celsius
From the mid18th to mid20th centuries, Fahrenheit was the system most widely used in Englishspeaking countries, while continental Europeans preferred 'The Swedish Scale'. With the drive to standardisation and metrication from the 1950s, Celsius became the adopted temperature scale for the EEC (later EU), with the UK and Ireland converting (somewhat reluctantly) after joining the European community.
This reluctance was partly due to human preference. For while the Celsius scale was developed for convenience, Fahrenheit's scale was based on observation and measurement. Also, whereas Fahrenheit had developed a ratio scale, Celsius had produced an interval scale. These are very different things, as we shall explain in a future article.
This may help explain why many people prefer Fahrenheit readings as rather closer to actual experience. In Celsius, a chilly day at 11°C does not seem greatly different from a really hot one at 35°C. On the Fahrenheit scale, these respectively measure at about 52°F and 95°F, with the latter traditionally taken as license for red top tabloids to start running 48 point headlines containing words like 'Phew', 'Flaming' and 'Scorcher'.
Incidentally, while the UK's Met Office started publishing temperatures in both Celsius and Fahrenheit from 1962 and dropping use of Fahrenheit altogether from official reports in 1970, British media persisted in using Fahrenheit in weather reports well into the 21st century. Indeed it became the fashion to use Celsius when describing extreme winter conditions and Fahrenheit for heat waves  a nice example of double standards in action.
Fahrenheit and Celsius formula
The formula to convert Fahrenheit to Celsius is:
[°C] = ([°F]  32) × 5/9
In other words, take your Fahrenheit reading, subtract 32, multiply the answer by five and then divide by nine. So 66 degrees Fahrenheit minus 32 would be 34, times five makes 170 divided by nine equals 18.88 recurring, or 18.9°C.
Celsius and Fahrenheit formula
[°F] = [°C] × 9/5 + 32
Here, you multiply your Celsius temperature by nine, divide by five and then add 32 to find the Fahrenheit reading.
So, 13 degrees Celsius times nine is 117, divided by five is 23.4, plus 32 makes 55.4°F.
Using decimals
To make life a little simpler, using decimals instead of fractions, you can use 1.8 instead of 9/5.
This gives the following modified formulae
 Celsius to Fahrenheit:
(°C + 40) × 1.8  40 = °F  Fahrenheit to Celsius:
(°F + 40) / 1.8  40 = °C
Trying this out bank city state action on a hot day (and remembering that multiplying by 1.8 is the same as doubling and then subtracting 10 per cent) we could have 36°C plus 40 is 76, times 1.8 is 136.8 minus 40 is 96.8°F, which is firmly in 'Scorcha' territory.
And the other way, on a rather chillier day, 48°F plus 40 is 88, divided by 1.8 is 48.88 recurring (48.9) minus 40 equals 8.9°C, which actually does sound quite cold.
Fahrenheit to Celsius reference chart
Celsius readings rounded citibank corporate mastercard login or down to single decimal points.
Celsius to Fahrenheit reference chart
Fahrenheit readings rounded up or down to nearest whole degree
Conversion units for the Temperature Converter
Celsius or Centigrade, Fahrenheit, Kelvin, Rankine, Reamur,
If you are cooking or baking, take a look at our charts for oven temperature conversions.
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