Celsius ↔ Fahrenheit
Convert °C to °F or °F to °C — updates as you type.
Convert °C to °F or °F to °C — updates as you type.
Celsius and Fahrenheit are two scales for measuring temperature. Celsius, used by most of the world and in science, sets the freezing point of water at 0° and the boiling point at 100° at sea level. Fahrenheit, still the everyday scale in the United States, puts those same points at 32° and 212°. Because the scales start at different zero points and use different-sized degrees, converting Celsius to Fahrenheit takes a multiply step and an add step, not just one multiplication.
People need this conversion more often than they expect. Imported appliances, ovens and thermostats may display Celsius. Product data sheets for paint, caulk, adhesives, concrete curing and sealants often list minimum application temperatures in °C. Weather forecasts while traveling, medical thermometers, aquarium heaters and recipes from outside the US are other common cases. A one-degree change in Celsius equals 1.8 degrees Fahrenheit, so small errors in Celsius become larger in Fahrenheit, which matters when a product label sets a hard minimum such as 5 °C (41 °F).
To use this tool, type a temperature into the Celsius (°C) box and the Fahrenheit (°F) value appears as you type. It works in reverse too: enter a number in the Fahrenheit box and the Celsius equivalent fills in automatically. Negative numbers and decimals are accepted, so you can convert freezer temperatures like −18 °C or body temperature like 37 °C. Results are rounded to two decimal places, which is more precision than any household or jobsite thermometer provides. The chart below lists common reference temperatures if you only need a quick lookup.
Multiply the Celsius temperature by 9/5 (or 1.8), then add 32. Formula: °F = °C × 9/5 + 32. Example: 25 °C × 1.8 = 45, and 45 + 32 = 77 °F.
To go the other way, subtract 32 from the Fahrenheit temperature and multiply by 5/9. Formula: °C = (°F − 32) × 5/9. Example: (68 − 32) × 5/9 = 20 °C. A quick mental estimate is to double the Celsius number and add 30; it is close for everyday weather but drifts at high and low temperatures.
Common Celsius to Fahrenheit conversions
| Celsius (°C) | Fahrenheit (°F) | Reference |
|---|---|---|
| −40 °C | −40 °F | Same on both scales |
| −18 °C | −0.4 °F | Typical freezer |
| 0 °C | 32 °F | Water freezes |
| 4 °C | 39.2 °F | Refrigerator |
| 10 °C | 50 °F | Cool day |
| 20 °C | 68 °F | Room temperature |
| 25 °C | 77 °F | Warm room |
| 30 °C | 86 °F | Hot day |
| 37 °C | 98.6 °F | Normal body temperature |
| 40 °C | 104 °F | Heat wave |
| 100 °C | 212 °F | Water boils at sea level |
| 180 °C | 356 °F | Moderate oven |
°F = (°C × 9/5) + 32
212°F — the boiling point of water.
32°F — the freezing point of water.
180 °C is 356 °F, which is why recipes often treat it as 350 °F. Likewise 200 °C is 392 °F (usually set as 400 °F) and 220 °C is 428 °F.
The two scales read the same at −40. Plugging −40 into the formula gives −40 × 1.8 + 32 = −40 °F.
No. 37 °C equals 98.6 °F, the commonly cited normal body temperature. A reading of 38 °C (100.4 °F) or higher is generally considered a fever.
Subtract 32, then multiply by 5/9. For example, 72 °F − 32 = 40, and 40 × 5/9 = 22.22 °C. You can also type the Fahrenheit value into this converter's °F box.
Double the Celsius number and add 30. For 15 °C that gives 60 °F, close to the exact 59 °F; the shortcut gets less accurate at very high temperatures such as oven settings.
Product labels vary, so always check the specific label. Common minimums are 5 °C (41 °F) and 10 °C (50 °F); convert the label's Celsius figure with this tool and compare it with the forecast.