Weather forecasts, ovens and thermometers disagree about which scale to use. The conversions are short formulas worth knowing.
The formulas
- Fahrenheit = Celsius × 9/5 + 32
- Celsius = (Fahrenheit − 32) × 5/9
- Kelvin = Celsius + 273.15
Examples
With the Temperature Converter:
- 100°C is 212°F, the boiling point of water at sea level.
- 98.6°F is 37°C, the traditional average body temperature.
- 0 K is −273.15°C, absolute zero.
A quick mental estimate from Celsius to Fahrenheit: double it and add 30. For 20°C that gives 70°F, close to the exact 68°F.
Using the converter
- Enter the temperature.
- Choose the scale to convert from and to.
- Read the result.
If you enter a value below absolute zero, such as −300°C, the tool says it is not physically possible instead of returning a number.
Good to know
- A temperature difference of 1 K equals 1°C, but 1°C is 1.8°F.
- The scales meet at −40, where Celsius and Fahrenheit are the same number.
- Oven temperatures vary by region, and “gas mark” is not covered.
Frequently asked questions
Why is Kelvin written without a degree sign?
It is an absolute scale and the official unit, so it is written simply as K.