The Formula
To convert any Fahrenheit temperature to Celsius:
°C = (°F − 32) × 5/9Also written as: °C = (°F − 32) ÷ 1.8 — both are identical.
Step-by-step example — converting 98.6°F (body temperature):
- 98.6 − 32 = 66.6
- 66.6 × 5 = 333
- 333 ÷ 9 = 37°C
Step-by-step example — converting 72°F (room temperature):
- 72 − 32 = 40
- 40 × 5 = 200
- 200 ÷ 9 = 22.2°C
Fahrenheit to Celsius Chart — 21 Common Temperatures
All the temperatures Americans encounter daily — weather, body temp, cooking — converted to Celsius:
| °F | °C | What it means |
|---|---|---|
| -40°F | -40°C | Fahrenheit = Celsius (only point) |
| -4°F | -20°C | Very cold winter |
| 14°F | -10°C | Freezing cold |
| 32°F | 0°C | Freezing point of water |
| 50°F | 10°C | Cool autumn day |
| 59°F | 15°C | Mild spring day |
| 68°F | 20°C | Comfortable room temperature |
| 70°F | 21.1°C | Typical indoor temperature (US) |
| 72°F | 22.2°C | Comfortable room temperature (US) |
| 77°F | 25°C | Warm summer day |
| 86°F | 30°C | Hot day |
| 95°F | 35°C | Very hot day / heat warning |
| 98.6°F | 37°C | Normal human body temperature |
| 100.4°F | 38°C | Fever threshold (adults) |
| 104°F | 40°C | High fever / heat wave |
| 212°F | 100°C | Boiling point of water (sea level) |
| 350°F | 176.7°C | Oven (baking — common US setting) |
| 375°F | 190.6°C | Oven (moderate) |
| 400°F | 204.4°C | Oven (moderate-high) |
| 425°F | 218.3°C | Oven (high heat) |
| 450°F | 232.2°C | Oven (very high — pizza) |
Mental Math Shortcut (No Calculator)
- Fast °F → °C: Subtract 30, then halve it. Example: 70°F → 70−30=40, 40÷2=20°C. (True: 21.1°C — good for estimates.)
- Fast °C → °F: Double it and add 30. Example: 20°C → 20×2=40, 40+30=70°F. (True: 68°F.)
- Key anchors: 32°F=0°C · 68°F=20°C · 98.6°F=37°C · 212°F=100°C
Going the Other Way?
Need to convert Celsius back to Fahrenheit? The formula is °F = (°C × 9/5) + 32. Use the °C → °F tab in the converter above, or see the full guide: Celsius to Fahrenheit — Converter & Chart.
For specific temperatures: 37°C in Fahrenheit (body temperature) · 100°C in Fahrenheit (boiling point)
Frequently Asked Questions
What is the formula to convert Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. Subtract 32 first, then multiply by 5/9. Example: 98.6°F → (98.6−32) × 5/9 = 37°C.
What is 98.6 Fahrenheit in Celsius?
98.6°F = 37°C — normal human body temperature. Calculation: (98.6−32) × 5/9 = 66.6 × 5/9 = 37°C.
What is 32 Fahrenheit in Celsius?
32°F = 0°C — the freezing point of water. Calculation: (32−32) × 5/9 = 0°C.
What is 72 Fahrenheit in Celsius?
72°F = 22.2°C — a comfortable room temperature. Calculation: (72−32) × 5/9 = 40 × 5/9 = 22.2°C.
What is 70 Fahrenheit in Celsius?
70°F = 21.1°C — typical indoor room temperature. Calculation: (70−32) × 5/9 = 38 × 5/9 = 21.1°C.
How do you convert Fahrenheit to Celsius without a calculator?
Mental shortcut: subtract 30, then halve the result. Example: 80°F → 80−30=50, 50÷2=25°C. True answer: 26.7°C. Close enough for everyday use.
What temperature is the same in both scales?
-40°. Both Fahrenheit and Celsius read -40 at this point — the only temperature where both scales are equal.