Celsius to Fahrenheit
Type a temperature in °C to read it in °F. The converter multiplies by 9/5 and adds 32, the exact relation between the two scales.
Formula: °F = °C × 9/5 + 32
| Degrees Celsius (°C) | Degrees Fahrenheit (°F) |
|---|---|
| -40 | -40 |
| -20 | -4 |
| -10 | 14 |
| 0 | 32 |
| 10 | 50 |
| 15 | 59 |
| 20 | 68 |
| 25 | 77 |
| Degrees Celsius (°C) | Degrees Fahrenheit (°F) |
|---|---|
| 30 | 86 |
| 37 | 98.6 |
| 40 | 104 |
| 50 | 122 |
| 60 | 140 |
| 80 | 176 |
| 100 | 212 |
The formula, step by step
- Multiply by 9/5
Or by 1.8: 25 °C × 1.8 = 45.
- Add 32
45 + 32 = 77 °F.
- Check
Water freezes at 0 °C = 32 °F and boils at 100 °C = 212 °F at sea level.
The 1.8 comes from the size of the degrees: between the freezing and boiling points of water there are 100 Celsius degrees but 180 Fahrenheit degrees. The 32 is the offset, because the Fahrenheit scale puts the freezing point at 32 instead of 0. NIST gives the exact relation in SP 811.
Fahrenheit is still the everyday scale in the United States and a few other places, while weather services almost everywhere else report in Celsius. For temperature differences, such as a rise of 10 °C, multiply by 1.8 but do not add 32: the rise is 18 °F. Adding the offset to a difference is the most common slip with this formula.
Cooking is where rounding matters least: ovens often run 10 °C off their dial, so the 350 °F in a US recipe and the 180 °C in a European one are effectively the same setting. Candy and frying thermometers are the exception, since sugar stages are only a few degrees apart.
Weather, cooking and fever
- 20–22 °C (68–72 °F) is a comfortable room.
- 37 °C is 98.6 °F, the textbook body temperature; 38 °C (100.4 °F) is usually treated as a fever.
- 180 °C, a common oven setting, is 356 °F, which US recipes round to 350 °F.
- −18 °C is about 0 °F, the usual freezer setting.
Celsius to Fahrenheit questions
What is 30 °C in Fahrenheit?
30 × 1.8 + 32 = 86 °F.
Where do the Celsius and Fahrenheit scales meet?
At −40. −40 °C and −40 °F are the same temperature.
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. 98.6 °F becomes 37 °C.
Is 40 °C hot?
Very. 40 °C is 104 °F, a heat-wave temperature in most places.