Celsius (°C) is used almost everywhere, while Fahrenheit (°F) is mainly used in the United States. So when reading American recipes, appliance manuals, or a weather forecast while traveling, you often need to convert one to the other. Let's go over the formula and a handy table.
Conversion formulas
Celsius to Fahrenheit:
°F = °C × 9/5 + 32
Fahrenheit to Celsius:
°C = (°F − 32) × 5/9
For example, 20 °C: 20 × 9/5 + 32 = 36 + 32 = 68 °F.
A quick mental shortcut
A rough estimate you can do in your head: multiply °C by 2 and add 30. For 20 °C, that gives 70 °F — close to the exact 68 °F. For everyday temperatures, that's often close enough.
Table of common values
| °C | °F | What it is |
|---|---|---|
| 0 | 32 | water freezes |
| 20 | 68 | room temperature |
| 36.6 | 97.9 | body temperature |
| 37 | 98.6 | body temperature (commonly cited as "normal" in °F) |
| 100 | 212 | water boils |
| 180 | 356 | oven, baking |
| 200 | 392 | oven, roasting |
Quick conversion online
To avoid doing the math by hand, especially with decimal values, use the temperature converter — enter a value in °C, °F, or Kelvin and get the rest instantly. Handy for recipes, appliances, and weather.
What about Kelvin
Science uses Kelvin (K): 0 K is absolute zero, and 0 °C = 273.15 K. The formula is simple: K = °C + 273.15. The temperature converter calculates that too.