Fahrenheit to Celsius

The exact conversion

Fahrenheit to Celsius is how you read a US forecast, a US thermostat, or an American recipe when you think in Celsius. Subtract 32 first, then multiply by 5/9: °C = (°F − 32) × 5/9. Freezing, 32 °F, becomes 0 °C. Boiling, 212 °F, becomes 100 °C. A pleasant room at 72 °F is 22.2 °C. Body temperature of 98.6 °F is 37 °C.

The formula used above is °C = (°F − 32) × 5/9. Both boxes stay in step, so you can start from either unit. Results are rounded for display; the factor itself is the legal definition, not a rounded shortcut.

Worked examples

Each line is the same formula with a new starting number. You can match it against the converter by typing the value on the left.

• 32 °F: (32 − 32) × 5/9 = 0 °C.
• 72 °F: (72 − 32) × 5/9 = 22.22 °C.
• 350 °F: (350 − 32) × 5/9 = 176.67 °C.

Where the rounding matters

Ovens are where the order of operations matters most. A recipe set to 350 °F is (350 − 32) × 5/9 = 176.7 °C, which cooks like a 180 °C oven. Four hundred degrees Fahrenheit is 204.4 °C. For weather, a rough trick is to subtract 30 and divide by 2: 80 °F is about 25 °C, and the exact value is 26.7 °C. That shortcut is fine for deciding whether to take a jacket. It is not fine for a fever or a roast.

Dividing by 2 before subtracting 32 gives nonsense, because the scales are shifted. Work from the formula in order: subtract 32, multiply by 5, divide by 9. Minus 40 is the identity check on both pages: −40 °F is −40 °C. If you need the other direction, the Celsius to Fahrenheit page adds 32 after scaling by 9/5.

Conversion table: fahrenheit to celsius