Convert Celsius, Fahrenheit and Kelvin
C to F to K, both directions, live.
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About this tool
Type a temperature and convert between Celsius, Fahrenheit and Kelvin instantly, using the exact formulas rather than approximations.
Useful for weather in other countries, oven settings in imported recipes, lab work in Kelvin, and settling arguments about whether 98.6 F is actually a fever. Runs locally in your browser.
How it works
- Type an amount and pick your currencies.
- The result updates live as you type.
- Swap the direction with one click.
Frequently asked questions
What is the formula for Celsius to Fahrenheit?
Multiply by 9/5 and add 32. So 20 C is 68 F. Going the other way, subtract 32 and multiply by 5/9.
What is Kelvin and when would I use it?
Kelvin is the scientific scale that starts at absolute zero, the coldest possible temperature. 0 C equals 273.15 K, and Kelvin steps are the same size as Celsius steps, so it is mostly a shift used in physics and chemistry.
At what temperature are Celsius and Fahrenheit equal?
At minus 40. It is the one point where both scales read the same number, and yes, you can verify it in the converter.