How to convert Fahrenheit to Celsius
Fahrenheit and Celsius are related by a formula rather than a single factor. Converting Fahrenheit to Celsius helps when reading US recipes, medical thermometers or weather forecasts in metric countries.
Fahrenheit to Celsius conversion table
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| -40 °F | -40 °C |
| -20 °F | -28.8888888889 °C |
| -10 °F | -23.3333333333 °C |
| 0 °F | -17.7777777778 °C |
| 10 °F | -12.2222222222 °C |
| 20 °F | -6.66666666667 °C |
| 25 °F | -3.88888888889 °C |
| 30 °F | -1.11111111111 °C |
| 37 °F | 2.77777777778 °C |
| 40 °F | 4.44444444444 °C |
| 50 °F | 10 °C |
| 100 °F | 37.7777777778 °C |
About the units
Fahrenheit (°F)
Fahrenheit sets water freezing at 32 °F and boiling at 212 °F; it is used in the US.
Celsius (°C)
Celsius sets water freezing at 0 °C and boiling at 100 °C at sea level.
How to use this converter
- Type the number of Fahrenheit (°F) in the input box.
- The result in Celsius appears instantly — no button needed.
- See the same value in every other temperature unit just below.
- Use “Swap units” to convert Celsius back to Fahrenheit.
When you’ll use the fahrenheit to celsius conversion
A US cookie recipe says to bake at 375 °F. Converting gives about 191 °C, so you set a metric oven to 190 °C.
A child’s thermometer reads 101.3 °F. Converting gives about 38.5 °C, which matches the units your doctor uses.
💡 For a quick estimate in your head, subtract 30 and halve it (70 °F → about 20 °C; exact 21.1 °C).
Watch out for these mix-ups
- Subtracting 32 after multiplying instead of before.
- Using the full formula to convert a change in temperature.
- Reporting a fever reading rounded to the nearest whole degree.
- Using a conventional oven temperature in a fan oven without adjusting.
Tips for better results
- Subtract 32, then multiply by 5/9.
- For differences, multiply by 5/9 without subtracting 32.
- Lower temperatures by about 20 °C for fan ovens.
💡 Practical tip: Fan-assisted ovens usually need a temperature about 20 °C lower than conventional ovens.
Frequently asked questions
How many Celsius are in one fahrenheit?
-17.2222222222 °C corresponds to 1 °F. Because this scale uses an offset or an inverse relationship, there is no single multiplication factor — use the formula above.
How do I convert Fahrenheit to Celsius?
Apply the formula shown on this page, or enter your value in the converter for an instant exact answer.
What is 37 °F in °C?
37 °F = 2.77777777778 °C. Also, 0 °F = -17.7777777778 °C and 100 °F = 37.7777777778 °C.
What is the difference between a fahrenheit and a celsius?
Fahrenheit sets water freezing at 32 °F and boiling at 212 °F; it is used in the US. Celsius sets water freezing at 0 °C and boiling at 100 °C at sea level.
Is this tool free and private?
Yes — the Fahrenheit to Celsius is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.
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