Celsius to Fahrenheit Conversion: Formula, Full Chart and Mental Math Tricks
°F = (°C × 9/5) + 32 — that's the exact Celsius to Fahrenheit formula. Quick version: multiply Celsius by 2, subtract 10%, add 32. For 20°C: 20×2=40, minus 4=36, plus 32=68°F. Use our Celsius to Fahrenheit converter for instant results, or reference the full chart below.
Celsius to Fahrenheit Formula (Exact and Approximate)
Exact: °F = (°C × 9/5) + 32
Quick mental math: °F ≈ (°C × 2) − (°C × 2 × 10%) + 32
Fahrenheit to Celsius: °C = (°F − 32) × 5/9
Quick Reference: Key Temperature Conversions
| Reference Point | Celsius (°C) | Fahrenheit (°F) |
|---|---|---|
| Water freezes | 0°C | 32°F |
| Cold winter day | -10°C | 14°F |
| Cool room temperature | 18°C | 64.4°F |
| Comfortable room temp | 20–22°C | 68–71.6°F |
| Warm spring day | 25°C | 77°F |
| Hot summer day | 35°C | 95°F |
| Normal body temperature | 37°C | 98.6°F |
| Fever threshold | 38°C | 100.4°F |
| Water boils | 100°C | 212°F |
| Celsius = Fahrenheit | -40°C | -40°F |
Full Celsius to Fahrenheit Conversion Chart
| °C | °F | °C | °F | °C | °F |
|---|---|---|---|---|---|
| -40 | -40.0 | 10 | 50.0 | 55 | 131.0 |
| -30 | -22.0 | 15 | 59.0 | 60 | 140.0 |
| -20 | -4.0 | 20 | 68.0 | 70 | 158.0 |
| -10 | 14.0 | 25 | 77.0 | 80 | 176.0 |
| 0 | 32.0 | 30 | 86.0 | 90 | 194.0 |
| 5 | 41.0 | 37 | 98.6 | 100 | 212.0 |
Oven Temperature Conversions
| Oven Setting | °C | °F | Gas Mark |
|---|---|---|---|
| Very low / slow cook | 120–130°C | 248–266°F | ½–1 |
| Low | 150°C | 302°F | 2 |
| Moderate | 180°C | 356°F | 4 |
| Standard baking | 190–200°C | 374–392°F | 5–6 |
| Hot (roasting) | 220°C | 428°F | 7 |
| Very hot (pizza) | 250°C | 482°F | 9 |
Mental Math Tricks for Fast Conversion
- °C to °F (fast): Double the Celsius value, subtract 10% of that, add 32. Example: 30°C → 60, minus 6 = 54, plus 32 = 86°F (exact: 86°F ✓)
- °F to °C (fast): Subtract 32, halve the result, add 10% back. Example: 68°F → 36, halve = 18, add 1.8 ≈ 19.8°C (exact: 20°C)
- Quick anchors to memorize: 0°C=32°F | 10°C=50°F | 20°C=68°F | 30°C=86°F | 40°C=104°F | 100°C=212°F
Conversion FAQ
What is the formula to convert Celsius to Fahrenheit?
°F = (°C × 9/5) + 32. Quick version: double °C, subtract 10%, add 32.
What is 37°C in Fahrenheit?
37°C = 98.6°F — normal human body temperature.
At what temperature are Celsius and Fahrenheit the same?
-40° — both scales are equal at exactly -40°C = -40°F.
How do you convert Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. Example: 98.6°F → (98.6−32) × 5/9 = 37°C.