Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin instantly.
Convert Celsius, Fahrenheit and Kelvin
This temperature converter switches instantly between the three main temperature scales: Celsius (°C), used in most of the world; Fahrenheit (°F), used in the United States; and Kelvin (K), the scientific standard. Type a temperature, choose your scales, and the result appears immediately — handy for cooking, weather, travel between the US and UK, and science.
The conversion formulas
To convert Celsius to Fahrenheit, multiply by 9/5 and add 32 (°F = °C × 9/5 + 32). To go from Fahrenheit to Celsius, subtract 32 and multiply by 5/9. Kelvin shares the size of a Celsius degree but starts at absolute zero, so K = °C + 273.15. The calculator applies the correct formula automatically for whatever scales you select.
Common temperature reference points
| Description | Celsius | Fahrenheit |
|---|---|---|
| Water freezes | 0 °C | 32 °F |
| Room temperature | 20 °C | 68 °F |
| Body temperature | 37 °C | 98.6 °F |
| Water boils | 100 °C | 212 °F |
Frequently asked questions
What is 100°F in Celsius?
100°F is about 37.8°C — close to normal body temperature. Subtract 32 and multiply by 5/9 to convert any Fahrenheit value.
Why do scientists use Kelvin?
Kelvin starts at absolute zero, the coldest possible temperature, so it has no negative values. This makes it ideal for physics and chemistry calculations.