Celsius to Fahrenheit converter, for ovens, weather and body temperature.

To convert Celsius to Fahrenheit, multiply the degrees Celsius by 1.8 and add 32. So 20 °C is 20 × 1.8 + 32 = 68 °F, 0 °C is 32 °F and 100 °C is 212 °F. It also works below zero: -10 °C is 14 °F. Unlike length and weight, temperature has a starting offset, so the multiplication alone is not enough.

How to use the converter

1. Type a temperature in the Degrees Celsius (°C) box. A minus sign works.
2. The big result shows Degrees Fahrenheit (°F). The card shows the same temperature in kelvin.
3. Type Fahrenheit in the second box to go back to Celsius, or open the Fahrenheit to Celsius converter page.
4. Click a row in Common values to load it. The Up and Down arrow keys step by 1 degree, and with Alt by 0.1.
5. Choose Decimals: 0 for the oven and the weather, 1 for a thermometer. Print chart gives an oven sheet.

The exact equation

NIST Handbook 44 (2026), Appendix C has a table headed "Conversion Equations for Units of Temperature (Exact)". It gives degree Fahrenheit = (degree Celsius × 1.8) + 32 and kelvin = degree Celsius + 273.15. Page checked 18 Oct 2026. Both 1.8 and 32 are exact, so every answer is exact up to the digits you choose to show. 37 °C is 98.6 °F, with nothing hidden in the formula.

Two shortcuts and how wrong they are

The popular one is to double the Celsius and add 30. It is good in mild weather and drifts as the number grows. The table shows how far off it is.

The better one is exact: double the number, take off a tenth of the double, and add 32. For 25 °C: 50, minus 5 is 45, plus 32 is 77 °F, which is the exact answer, 77 °F. That works because 2 − 0.2 is 1.8. So the first shortcut is fine for weather and no good for an oven, where 180 °C by the shortcut would be 390 °F against 356 °F.

Worked examples

• A room at 21 °C. 21 × 1.8 = 37.8, plus 32 is 69.8 °F.
• A hot day, 35 °C. 35 × 1.8 = 63, plus 32 is 95 °F.
• A cold morning, -5 °C. -5 × 1.8 = -9, plus 32 is 23 °F.
• An oven at 180 °C. 180 × 1.8 = 324, plus 32 is 356 °F. A recipe that says 350 °F is 176.7 °C, so the 350 °F recipe is 3.3 °C below a 180 °C setting.
• A thermometer at 37 °C. 37 × 1.8 = 66.6, plus 32 is 98.6 °F.

Oven temperatures in Celsius

The table gives each setting in exact Fahrenheit and the nearest 5 °F. It converts the number on the dial only. It does not adjust for a fan oven or a gas mark, so read the recipe for that.

180 °C is exactly 356 °F, which is 6 °F above 350 °F. Whether a gap like that matters depends on the recipe.

Weather abroad, and body temperature as a number

For weather, remember that every 5 °C is exactly 9 °F. That gives a short ladder you can learn: 0 °C is 32 °F, 10 °C is 50, 20 °C is 68, 30 °C is 86 and 40 °C is 104. For a body temperature, 37 °C is 98.6 °F, 38 °C is 100.4 °F and 39 °C is 102.2 °F. This page only turns one number into the other. It cannot tell you whether a reading is normal or what to do about it, so ask a doctor or a health service for that.

Mistakes that are specific to Celsius to Fahrenheit

The most common is forgetting the 32 and giving 20 × 1.8 = 36 °F for 20 °C. The right answer is 68 °F. The second is mixing a reading with a change. A reading of 10 °C is 50 °F, but a rise of 10 °C is a rise of 18 °F, because the 32 is only for positions on the scale, not for differences. The third is the minus sign: -10 °C is 14 °F, not 10 °F. The fourth is a thermometer that says °F when you thought it said °C. Check the letter: 100 °C is 212 °F, but 100 °F is only 37.8 °C.

Who uses Celsius to Fahrenheit

Cooks using a UK, European or Australian recipe on an American oven. Travellers who read a forecast in Celsius. Parents reading a thermometer. Students and anyone setting a fridge, a freezer or an aquarium. For the opposite direction use the Fahrenheit to Celsius converter. For kitchen volume see the Ounces to cups converter.