How to use it
- Enter the temperature in °F.
- Read the result in °C and K.
- Use the charts for oven and body temperatures.
- Swap the direction with the ⇄ button for °C to °F.
The formula
°C = (°F − 32) × 5/9
Subtract 32 first, then multiply by 5/9 (about 0.5556). The order matters: multiplying first gives a wrong answer.
Example: 72 °F → (72 − 32) × 5/9 = 40 × 5/9 = 22.22 °C, a comfortable room temperature.
Kelvin, the scientific scale, is °C + 273.15, so 72 °F is 295.37 K. The two scales meet at −40, where −40 °F equals −40 °C.
Weather and body temperature
| °F | °C | |
|---|---|---|
| 0 °F | −17.78 °C | Very cold winter day |
| 32 °F | 0 °C | Water freezes |
| 50 °F | 10 °C | Cool |
| 72 °F | 22.22 °C | Room temperature |
| 86 °F | 30 °C | Hot summer day |
| 98.6 °F | 37 °C | Typical body temperature |
| 100 °F | 37.78 °C | Fever range for many adults |
| 212 °F | 100 °C | Water boils at sea level |
What counts as a fever depends on age and how the temperature is taken; follow your doctor's guidance rather than a single cutoff.
Oven temperatures
US recipes give oven temperatures in Fahrenheit; most of the world uses Celsius, and older British recipes use gas marks.
| °F | °C (exact) | Usual °C setting | Gas mark |
|---|---|---|---|
| 325 °F | 162.78 °C | 160 °C (fan 140 °C) | 3 |
| 350 °F | 176.67 °C | 180 °C (fan 160 °C) | 4 |
| 375 °F | 190.56 °C | 190 °C (fan 170 °C) | 5 |
| 400 °F | 204.44 °C | 200 °C (fan 180 °C) | 6 |
| 425 °F | 218.33 °C | 220 °C (fan 200 °C) | 7 |
| 450 °F | 232.22 °C | 230 °C (fan 210 °C) | 8 |
Recipes round to the nearest 10 °C, and fan (convection) ovens usually run about 20 °C lower for the same result.
Quick mental math
Subtract 30 and halve it. 72 °F → 42 → 21 °C (the exact answer is 22.2). The shortcut is close for everyday weather but drifts at high temperatures: for 350 °F it gives 160 °C instead of 177 °C, so don't use it for baking.
A few anchors help too: 50 °F = 10 °C, 68 °F = 20 °C, 86 °F = 30 °C, 104 °F = 40 °C.
Where Fahrenheit is used
The United States uses Fahrenheit for weather, cooking and medicine, along with a few other places such as the Bahamas, the Cayman Islands, Liberia and Palau. Most other countries, and science everywhere, use Celsius. The value you type is saved in the page link, so the Share button sends the exact conversion.
To go the other way, use the Celsius to Fahrenheit converter.
Frequently asked questions
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9. 72 °F is (72 − 32) × 5/9 = 22.22 °C.
What is 350 °F in Celsius?
176.67 °C. Recipes round it to 180 °C, or 160 °C in a fan oven.
What is 98.6 °F in Celsius?
Exactly 37 °C, the traditional figure for normal body temperature.
When are Fahrenheit and Celsius equal?
At −40 degrees: −40 °F equals −40 °C.
Sources
- NIST – Special Publication 811: Guide for the Use of the International System of Units
- NIST – SI units: temperature
Last updated: November 14, 2026