How to convert Fahrenheit to Celsius
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. The formula is °C = (°F − 32) × 5/9. For example, 212°F = (212 − 32) × 5/9 = 100°C (boiling point). 32°F = 0°C (freezing point). 98.6°F = 37°C (normal body temperature).
Common temperature reference points
−40°F = −40°C (scales meet here) | 32°F = 0°C (water freezes) | 68°F = 20°C (room temperature) | 98.6°F = 37°C (body temperature) | 212°F = 100°C (water boils at sea level).
Frequently Asked Questions
At what temperature are Fahrenheit and Celsius equal?
At −40°. This is the only temperature where the Fahrenheit and Celsius scales give the same reading. You can verify this with the formula: −40°F = (−40 − 32) × 5/9 = −72 × 5/9 = −40°C.
Is there a quick mental approximation?
A rough estimate: subtract 30 from the Fahrenheit temperature and halve it. For example, 70°F ≈ (70 − 30) / 2 = 20°C (actual: 21.1°C). This is faster for mental math but not exact.