How to convert degrees Celsius to degrees Fahrenheit
Enter a temperature in degrees Celsius and read it in degrees Fahrenheit. The result updates as you type, and negative temperatures work.
Unlike most conversions, this one cannot be done by multiplying alone: the two scales start at different points, so it needs a multiplication and an addition.
Formula: °F = °C × 9/5 + 32
- Multiply the Celsius temperature by 9/5 (1.8).
- Add 32.
- For a quick estimate in your head, double the number, take off 10% of that, and add 32. For 20 °C: double is 40, minus 4 is 36, plus 32 is 68. That method is exact: doubling and then taking off 10% multiplies by 2 × 0.9, which is 1.8.
Common conversions
| Degrees Celsius (°C) | Degrees Fahrenheit (°F) |
|---|---|
| -40°C | -40°F |
| -20°C | -4°F |
| -10°C | 14°F |
| 0°C | 32°F |
| 10°C | 50°F |
| 20°C | 68°F |
| 25°C | 77°F |
| 30°C | 86°F |
| 37°C | 98.6°F |
| 100°C | 212°F |
Values are computed by the same converter as above, rounded to six significant digits. Need the other direction? See Fahrenheit to Celsius.
Worked examples
A pleasant room
20°C = 68°F.
Normal body temperature
37°C = 98.6°F. Body temperature varies by person and time of day, so 37 °C is an average, not a fixed value.
An oven
180°C = 356°F. Ovens are often marked in round numbers, so 180 °C on a UK dial is 350 °F on a US one.
Where the scales meet
-40°C = -40°F. This is the one temperature where both scales agree.
Things to keep in mind
- This converts a temperature reading. A temperature difference converts differently: a rise of 10 °C is a rise of 18 °F, with no 32 to add.
- Nothing can be colder than absolute zero, −273.15 °C (−459.67 °F). The converter rejects anything below it.
- Kelvin uses the same size of degree as Celsius but starts at absolute zero. Use the temperature converter to include kelvins.