Unit converter
Fahrenheit to Celsius Converter
Read an American Fahrenheit figure and get the Celsius value at once. US forecasts, recipe ovens and thermometers all report in Fahrenheit, so anyone outside the United States meeting those numbers needs to flip them into the scale they think in. Enter a temperature in degrees Fahrenheit and the tool shows degrees Celsius, alongside a table of the values looked up most. It helps when planning a trip from a US weather app, baking from an American cookbook, or judging whether a Fahrenheit fever reading is something to worry about.
Common Fahrenheit to Celsius values
| Fahrenheit | Celsius |
|---|---|
| 0 °F | -17.7778 °C |
| 32 °F | 0 °C |
| 50 °F | 10 °C |
| 68 °F | 20 °C |
| 98.6 °F | 37 °C |
| 100 °F | 37.7778 °C |
| 212 °F | 100 °C |
How to convert
- Begin with the temperature in degrees Fahrenheit.
- Subtract 32 first, removing the offset between the two zero points.
- Multiply what remains by 5/9, the reciprocal of the 9/5 used the other way.
- The number you end with is the temperature in degrees Celsius.
- For a rough guess in your head, take 30 off the Fahrenheit value and halve it: 70°F gives about 20°C, near the true 21.1°C.
°C = (°F - 32) × 5/9
These two scales are affine, meaning they differ in both degree size and zero point. You first take 32 off the Fahrenheit reading to align the freezing point with zero, then shrink the result by 5/9 because a Fahrenheit degree is smaller than a Celsius one. The subtraction must come before the multiplication for the answer to be correct.
- °F
- the temperature in degrees Fahrenheit you start with
- 32
- the Fahrenheit value at which water freezes, removed as an offset
- 5/9
- the ratio of a Celsius degree to a Fahrenheit degree
Worked example
A US forecast of 86°F becomes 86 minus 32, which is 54, then times 5/9, giving 30°C. A hot oven set to 350°F is 350 minus 32 (that is 318) times 5/9, about 176.7°C.
Key facts
- Water freezes at 32°F, which is 0°C.
- Water boils at 212°F, equal to 100°C.
- A normal body reading of 98.6°F is 37°C.
- The scales coincide at -40: -40°F is exactly -40°C.
Tips
- The subtract-30-then-halve shortcut is quick for weather and lands within a degree or two of the real value.
- Convert an American oven setting once and note the Celsius number so you can set your dial without rechecking.
Frequently asked questions
What is 98.6°F in Celsius?+
98.6°F is (98.6 - 32) × 5/9, which works out at 37°C, the usual normal body temperature.
Why subtract 32 before multiplying?+
Fahrenheit sets freezing water at 32, not zero, so you strip that offset away before rescaling, otherwise the 5/9 acts on the wrong starting point.
What is room temperature in Celsius?+
A comfortable 68°F to 72°F room sits at roughly 20°C to 22°C once converted.
Does this conversion lose any accuracy?+
No. °C = (°F - 32) × 5/9 is an exact definition; any rounding is purely the decimal places shown on screen.
Things to watch
- Do not halve the Fahrenheit figure on its own; skipping the -32 step throws every reading off, badly so at high temperatures.
Sources
Last updated: 2026-01-01
Conversions use internationally defined factors. Provided for general use; verify critical measurements independently.