The Farenheit to Celcius conversion is really the temperature conversion from degrees Fahrenheit to degrees Celsius. The names of the two temperature scales are easy to misspell, so you can avoid them by using the symbols °F and °C. Fortunately, converting between the temperatures is easier than spelling their names. Here’s how to do it, along with example calculations.
°F to °C Formula
There are two common formulas for converting °F to °C:
- °C = 5/9(°F – 32)
- °C =(°F – 32) ÷ 1.8
It does not matter which formula you use. You’ll get the same answer.
Easiest Way to Convert Farenheit to Celcius
Basically, you take the Fahrenheit temperature, subtract 32 from it, and then either multiply by 5/9 or else divide by 1.8. There’s less chance of making a mistake if you avoid the fraction, so dividing by 1.8 is the easiest option.
- Start with the temperature in °F and subtract 32.
- Take the answer and divide it by 1.8. This is the answer in °C.
Calculators don’t all handle order of operations the same way, so it’s important to get the answer for “F – 32” before dividing by 1.8! For example, enter the °F temperature, the minus sign, 32, the equal sign, the divide symbol, 1.8, and then the equal sign.
Convert °F to °C
For example, convert 90 °F to °C.
°C = (°F – 32) ÷ 1.8
°C = (90 – 32) ÷ 1.8 = 58 ÷ 1.8 = 32.2 °C
Convert °C to °F
It’s just as easy working the temperature conversion the other way, from °C to °F.
- °F = 9⁄5°C + 32
- °F = 1.8 °C + 32
Once again, you don’t need to work with fractions.
For example, convert 20 °C to °F.
°F = 1.8 °C + 32
°F = (1.8)(20) + 32 = 36 + 32 = 68 °F
Most calculators handle the math just fine if you do 1.8 x 20 + 32, but if you’re worried, enter 1.8 x 20 = + 32 =.
Table of °F to °C Temperatures
Here is a handy table of important temperatures in both °F and °C:
| Temperature | Celsius | Fahrenheit |
|---|---|---|
| Absolute zero | −273.15 | −459.67 |
| Water freezing point | 0.00 | 32.00 |
| Water triple point | 0.01 | 32.018 |
| Average temperature of Earth | 15 | 59 |
| Typical room temperature | 22 | 71.6 |
| Human body temperature | 37 | 98.6 |
| Water boiling point | 100 | 212 |
References
- Balmer, Robert T. (2010). Modern Engineering Thermodynamics. Academic Press. ISBN 978-0-12-374996-3.
- Boyes, Walt (2009). Instrumentation Reference Book. Butterworth-Heinemann. ISBN 978-0-7506-8308-1.
- Buchdahl, H. A. (1966). The Concepts of Classical Thermodynamics. Cambridge U.P. ISBN 978-0-521-04359-5.
- Helrich, Carl S. (2009). Modern Thermodynamics With Statistical Mechanics. Berlin, Heidelberg: Springer Berlin Heidelberg. ISBN 978-3-540-85417-3.