Convert °F to °C instantly. Formula: °C = (°F − 32) × 5/9.
°C = (°F − 32) × 5/9
Subtract 32, then multiply by 5/9 (or divide by 1.8).
| Fahrenheit | Celsius |
|---|---|
| -40°F | -40.00°C |
| 0°F | -17.78°C |
| 32°F | 0.00°C |
| 50°F | 10.00°C |
| 72°F | 22.22°C |
| 98.6°F | 37.00°C |
| 100°F | 37.78°C |
| 212°F | 100.00°C |
| 350°F | 176.67°C |
| 400°F | 204.44°C |
The formula °C = (°F − 32) × 5/9 contains two separate adjustments for two different problems. Subtracting 32 corrects for the different zero points: water freezes at 32°F but 0°C, so you must remove 32 before scaling. Multiplying by 5/9 corrects for the different interval sizes: there are 180 Fahrenheit degrees between water's freezing point (32°F) and boiling point (212°F), but only 100 Celsius degrees for the same range. The ratio 100/180 simplifies to 5/9 ≈ 0.5556. These two adjustments — shifting the zero point and rescaling the intervals — are applied in the correct order (subtract first, then scale) to get the exact Celsius equivalent.
A practical mental shortcut for everyday weather temperatures: subtract 32, then halve the result (instead of multiplying by 5/9 = 0.556). This approximation overstates the conversion slightly — at 72°F, exact = 22.2°C vs. approximate = 20°C — but gives a quick working estimate.
Body temperature: Normal human body temperature is 98.6°F = 37.0°C exactly. A fever begins above 100.4°F = 38°C. A high fever requiring urgent care is typically above 103°F = 39.4°C. If a doctor abroad tells you the patient has a temperature of "38.5," that means 101.3°F.
Oven temperatures for cooking: American recipes list oven temperatures in Fahrenheit; European recipes use Celsius. 325°F = 162.8°C (slow cooking). 350°F = 176.7°C (standard baking). 375°F = 190.6°C. 400°F = 204.4°C (roasting). 425°F = 218.3°C (high heat, pizza). 450°F = 232.2°C (very hot).
Weather: 0°F = −17.8°C (very cold, sub-zero). 32°F = 0°C (water freezes, snow likely). 50°F = 10°C (cool, need a jacket). 68°F = 20°C (comfortable spring day). 86°F = 30°C (warm summer). 100°F = 37.8°C (dangerously hot, heatwave conditions).
Swimming pool temperature: A comfortable outdoor pool is around 78–82°F = 25.6–27.8°C. Competition pools are maintained at 77–82°F = 25–27.8°C per FINA standards. A hot tub is typically 100–104°F = 37.8–40°C.
| Fahrenheit | Celsius | Context |
|---|---|---|
| -40°F | -40°C | Both scales equal |
| 32°F | 0°C | Water freezes |
| 50°F | 10°C | Cool day |
| 68°F | 20°C | Comfortable room |
| 72°F | 22.2°C | Ideal room temp |
| 98.6°F | 37°C | Normal body temp |
| 100°F | 37.8°C | Low fever |
| 212°F | 100°C | Water boils |
| 350°F | 176.7°C | Baking temp |
| 400°F | 204.4°C | Roasting temp |
Fahrenheit to Celsius is one of the most critical unit conversions for international travelers, expats, and anyone following foreign recipes or reading international media. The United States is the only major country that uses Fahrenheit for everyday weather, cooking, and medical temperatures. Americans visiting Europe, Asia, Australia, or anywhere else encounter Celsius immediately — on weather apps, oven dials, thermostats, and medical thermometers. A weather forecast of "28°C" or an oven recipe calling for "180°C" requires this conversion for an American to act on it. Medical providers internationally use Celsius; a fever of "38.9°C" in a European hospital record means 102°F. Cooking from international recipes — European baking, Japanese cuisine, British cooking shows — always requires oven temperature conversion from Celsius to Fahrenheit.
°C = (°F − 32) × 5/9. Subtract 32 from the Fahrenheit value, then multiply by 5/9 (or divide by 1.8).
98.6°F is exactly 37°C, which is normal human body temperature.
72°F = (72 − 32) × 5/9 = 40 × 5/9 = 22.22°C. This is a comfortable room temperature.
−40°F = −40°C. This is the only temperature where both scales have the same value.
32°F = 0°C. This is the freezing point of water.
For all temperature conversions, see the full Temperature Converter.