Last updated: September 2026
Temperature conversion
Fahrenheit to Celsius (°F to °C)
Useful for travel weather, cooking instructions, thermostats, and health readings reported in Fahrenheit.
1 °F
-17.2222222222 °C
°C = (°F − 32) × 5/9
The formula
How to convert fahrenheit to celsius
Apply °C = (°F − 32) × 5/9. For example, -40 °F equals -40 °C.
Precision
Accurate constants, readable results
OmniUnit calculates with the full stored conversion factor, then displays up to 12 significant digits.
Common fahrenheit conversions
| Fahrenheit | Celsius |
|---|---|
| -40 °F | -40 °C |
| 32 °F | 0 °C |
| 50 °F | 10 °C |
| 68 °F | 20 °C |
| 77 °F | 25 °C |
| 212 °F | 100 °C |
Related temperature conversions
Frequently asked questions
What is the Fahrenheit to Celsius formula?
°C = (°F − 32) × 5/9. Subtract 32 from the Fahrenheit temperature, then multiply by 5/9 (0.5556). For example, 68 °F is (68 − 32) × 5/9 = 20 °C.
What is the Celsius to Fahrenheit formula?
°F = (°C × 9/5) + 32. Multiply the Celsius temperature by 9/5 (1.8), then add 32. To convert Celsius back to Fahrenheit, use the celsius-to-fahrenheit page, which shows the exact formula and a quick calculator.
How do I convert Fahrenheit to Celsius without a calculator?
Subtract 32 from the Fahrenheit degrees, then halve the result — close to the exact multiply-by-5/9. For 68 °F: 68 − 32 = 36, and half is 18 °C — the exact answer is 20 °C.
What is normal body temperature in Celsius?
98.6 °F equals exactly 37 °C — the standard normal body temperature. (98.6 − 32) × 5/9 = 37, which makes it a handy anchor for sanity-checking any Fahrenheit-to-Celsius conversion.