Temperature Converter
Convert a temperature between Celsius, Fahrenheit and Kelvin. Type a value and read off every scale.
About the Temperature Converter
This tool converts a temperature between the three common scales: Celsius, Fahrenheit and Kelvin. Unlike most converters it cannot just multiply by a factor, because Celsius and Fahrenheit have different zero points, so it applies the correct offset-and-scale formula for each direction.
How to use it
- Enter the reading you have in the matching field, for example a weather temperature in Celsius.
- Read the converted value from the Fahrenheit and Kelvin fields instantly.
- Type into any scale to convert the other way, including Kelvin for scientific work.
The formulas used are F = C x 9/5 + 32 and K = C + 273.15. A common check: water freezes at 0 C, 32 F and 273.15 K, and boils at 100 C, 212 F and 373.15 K. The scales meet at -40, where Celsius and Fahrenheit read the same number. All conversions run in your browser, so nothing you type leaves your device.
Frequently asked questions
What is the formula to convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 (1.8) and add 32. For example, 20 C becomes 20 x 1.8 + 32 = 68 F.
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, 98.6 F becomes (98.6 - 32) x 5/9 = 37 C, normal body temperature.
At what temperature do Celsius and Fahrenheit read the same?
At -40 degrees. Minus 40 Celsius equals minus 40 Fahrenheit, the single point where the two scales cross.
How is Kelvin related to Celsius?
Kelvin uses the same degree size as Celsius but starts at absolute zero. Add 273.15 to a Celsius value to get Kelvin, so 0 C is 273.15 K.