You’re traveling in Europe and the weather app says it’s 22°C outside. Is that warm enough for shorts? Or should you grab a jacket? If you grew up with Fahrenheit, Celsius can feel like a foreign language.
Whether you’re traveling, cooking with a foreign recipe, or just curious, here’s how to convert between the two temperature scales — including some tricks so you can do it in your head.
The Conversion Formulas
There are two formulas you need:
Fahrenheit to Celsius: °C = (°F - 32) × 5/9
Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Example — 72°F to Celsius:
- (72 - 32) × 5/9 = 40 × 0.556 = 22.2°C
Example — 30°C to Fahrenheit:
- (30 × 9/5) + 32 = 54 + 32 = 86°F
Quick Reference Chart
Here are the conversions you’ll use most often:
| Fahrenheit | Celsius | Context |
|---|---|---|
| 32°F | 0°C | Water freezes |
| 50°F | 10°C | Cool — need a jacket |
| 59°F | 15°C | Mild — light layers |
| 68°F | 20°C | Comfortable room temp |
| 72°F | 22°C | Ideal indoor temperature |
| 77°F | 25°C | Warm and pleasant |
| 86°F | 30°C | Hot summer day |
| 95°F | 35°C | Very hot |
| 100°F | 37.8°C | Normal body temperature |
| 104°F | 40°C | Heat wave / fever |
| 212°F | 100°C | Water boils |
| 350°F | 177°C | Common baking temperature |
| 400°F | 204°C | High baking temperature |
| 450°F | 232°C | Pizza oven temperature |
Mental Math Tricks
You don’t need exact precision for most situations. These shortcuts get you close enough:
Quick Fahrenheit to Celsius: Subtract 30, then divide by 2.
- 80°F → (80 - 30) ÷ 2 = 25°C (actual: 26.7°C — close enough!)
- 50°F → (50 - 30) ÷ 2 = 10°C (actual: 10°C — perfect!)
Quick Celsius to Fahrenheit: Double it, then add 30.
- 20°C → (20 × 2) + 30 = 70°F (actual: 68°F — close!)
- 35°C → (35 × 2) + 30 = 100°F (actual: 95°F — reasonable estimate)
These shortcuts are accurate within a few degrees — more than good enough for deciding what to wear.
Temperature Scales for Cooking
Cooking with international recipes requires accurate conversion. Here are common oven temperatures:
| Gas Mark | Fahrenheit | Celsius | Description |
|---|---|---|---|
| 2 | 300°F | 150°C | Slow |
| 4 | 350°F | 180°C | Moderate |
| 5 | 375°F | 190°C | Moderately hot |
| 6 | 400°F | 200°C | Hot |
| 7 | 425°F | 220°C | Hot |
| 8 | 450°F | 230°C | Very hot |
Convert Temperatures Instantly
For precise conversions, use our free temperature converter. We also have a full suite of unit converters for length, weight, and more.