How to use the temperature converter
- Type a number in the left box and choose the unit you are converting from.
- Choose the unit you want to convert to on the right — the answer appears instantly. You can also type in the right-hand box to convert the other way.
- Press ⇄ to swap the units, or Copy result to paste the answer elsewhere. The table underneath shows your value in every temperature unit at once.
Results are calculated with exact, internationally agreed conversion factors and shown to up to ten significant figures, so they are suitable for homework, cooking, travel, engineering and shopping alike. Bookmark a conversion by adding ?v=10&from=…&to=… to the page address.
Temperature conversion formulas
| Convert | Formula |
|---|---|
| °C → °F | °F = °C × 9/5 + 32 |
| °F → °C | °C = (°F − 32) × 5/9 |
| °C → K | K = °C + 273.15 |
| K → °C | °C = K − 273.15 |
| °F → K | K = (°F − 32) × 5/9 + 273.15 |
Quick mental trick: to estimate Fahrenheit from Celsius, double the Celsius number and add 30. For 20 °C: 20 × 2 + 30 = 70 °F (exact answer 68 °F). Going the other way, subtract 30 and halve.
Common temperatures
| What | °C | °F |
|---|---|---|
| Water freezes | 0 | 32 |
| Cool room | 18 | 64.4 |
| Room temperature | 20–22 | 68–72 |
| Normal body temperature | 37 | 98.6 |
| Fever | 38 | 100.4 |
| Hot summer day | 35 | 95 |
| Water boils (sea level) | 100 | 212 |
| Bake a cake | 180 | 356 |
| Pizza oven | 230 | 446 |
| Same in both scales | −40 | −40 |
The temperature scales
- Celsius (°C) is used by almost every country. 0 °C is the freezing point and 100 °C the boiling point of water at sea level.
- Fahrenheit (°F) is used mainly in the United States and a few Caribbean nations. Water freezes at 32 °F and boils at 212 °F.
- Kelvin (K) is the scientific scale. It starts at absolute zero (−273.15 °C), the coldest possible temperature, and uses the same step size as Celsius. Kelvin is written without a degree sign.
- Rankine (°R) is the absolute version of Fahrenheit, still used in some US engineering work.
Oven temperatures
Recipes from the US list oven temperatures in Fahrenheit, while European and Australian recipes use Celsius (and fan ovens run about 20 °C lower). 350 °F is 177 °C (usually rounded to 180 °C), 375 °F is 190 °C, 400 °F is 204 °C and 425 °F is 218 °C.
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 (or 1.8) and add 32. Example: 25 °C × 1.8 + 32 = 77 °F.
How do I convert Fahrenheit to Celsius?
Subtract 32 and multiply by 5/9. Example: (100 °F − 32) × 5/9 = 37.8 °C.
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees: −40 °C equals −40 °F.
Is 37 °C a fever?
37 °C (98.6 °F) is a typical normal body temperature. A fever is usually 38 °C (100.4 °F) or higher.