How to convert °C to °F
- 1.
Enter a temperature
Type a value; negative numbers such as −5 are allowed.
- 2.
Pick scales
The default is °C to °F; you can also choose kelvins (K).
- 3.
Read the result
The result updates live; swap the direction with the arrows button.
Temperature conversion formulas
The three scales are linked by simple linear formulas:
| Conversion | Formula |
|---|---|
| °C → °F | °F = °C × 9/5 + 32 (i.e. °C × 1.8 + 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 |
Example: 25 °C × 1.8 + 32 = 45 + 32 = 77 °F. Back again: (77 − 32) × 5/9 = 25 °C. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea-level pressure. The two scales meet at −40.
Key temperatures
| °C | °F | K | Description |
|---|---|---|---|
| −273.15 | −459.67 | 0 | absolute zero |
| −40 | −40 | 233.15 | scales meet |
| 0 | 32 | 273.15 | water freezes |
| 20 | 68 | 293.15 | room temperature |
| 30 | 86 | 303.15 | hot day |
| 36.6 | 97.88 | 309.75 | typical body temperature |
| 37 | 98.6 | 310.15 | textbook "normal" in the US |
| 38 | 100.4 | 311.15 | fever threshold |
| 100 | 212 | 373.15 | water boils |
Oven temperatures: °F to °C
US recipes give baking temperatures in °F. 350 °F = (350 − 32) × 5/9 = 176.7 °C, usually set as 180 °C.
| °F | °C (exact) | Typical setting | UK gas mark |
|---|---|---|---|
| 325 °F | 162.8 °C | 160-165 °C | 3 |
| 350 °F | 176.7 °C | 175-180 °C | 4 |
| 375 °F | 190.6 °C | 190 °C | 5 |
| 400 °F | 204.4 °C | 200 °C | 6 |
| 425 °F | 218.3 °C | 220 °C | 7 |
| 450 °F | 232.2 °C | 230 °C | 8 |
For a fan (convection) oven, recipes usually suggest lowering the temperature by about 20 °C (around 25 °F). Gas marks are approximate and vary slightly between oven makers.
Common mistake: temperature differences
The +32 in the formula applies to an actual temperature, not to a change. A rise of 10 °C is a rise of 18 °F, not 50 °F, and lowering an oven by 20 °C means lowering it by 36 °F. A kelvin and a degree Celsius have the same size, so differences are identical in both scales. The mental shortcut "double it and add 30" is exact only at 10 °C; at 30 °C it gives 90 °F instead of 86 °F. Also note that kelvins are written without a degree sign: 300 K, not 300 °K.
Frequently asked questions
How do I convert Celsius to Fahrenheit?
+
Multiply by 1.8 and add 32. Example: 20 °C × 1.8 + 32 = 68 °F.
How do I convert Fahrenheit to Celsius?
+
Subtract 32 and multiply by 5/9. Example: (100 − 32) × 5/9 = 37.8 °C.
What is 350 °F in Celsius?
+
350 °F = 176.7 °C - usually set as 175-180 °C on an oven.
What is a normal body temperature in Fahrenheit?
+
About 97.9-98.6 °F, which is 36.6-37 °C. A reading of 100.4 °F (38 °C) or more is usually treated as a fever.
What is 0 K in Celsius?
+
0 K = −273.15 °C = −459.67 °F (absolute zero). No lower temperature exists.
At what temperature are Celsius and Fahrenheit equal?
+
At −40: −40 °C = −40 °F.
Updated: