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Fahrenheit to Celsius

Convert °F to °C for weather, ovens and thermostats.

Inputs
°F

The number of fahrenheit to convert.

Celsius
22.2°C
In kelvin
295.37K
32 °F
0°C
72 °F
22.2°C
98.6 °F
37°C
212 °F
100°C
°C = (°F − 32) × 5/9

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Subtract 32, then divide by 1.8. The subtraction comes first because the scales place zero differently — 32 °F is the freezing point of water, which is 0 °C.

How to use Fahrenheit to Celsius

  1. Enter the temperature in Fahrenheit. Negative values are fine.
  2. Read the Celsius. To one decimal, with kelvin underneath.

About converting Fahrenheit to Celsius

Converting Fahrenheit to Celsius is the direction most people need, because the majority of published temperatures — weather forecasts, scientific figures, appliance settings, medical guidance — are in Celsius, while a large body of recipes, older technical documentation and American everyday usage is not. The arithmetic is simple, but the order matters: the 32 must come off before dividing, because it is an offset between the zeros of the two scales rather than a scaling factor. Divide first and the answer is right at exactly one temperature and wrong at every other. Two practical notes. Oven temperatures are conventionally rounded rather than converted precisely — 350 °F is 176.7 °C and every recipe writes 180, because domestic ovens vary by more than that from front to back and a stated dial figure is a target rather than a measurement. And temperature intervals are not temperatures: if a forecast says a five-degree Fahrenheit drop, that is 2.8 Celsius degrees of change, not the result of converting 5 °F. Confusing the two is the single most common error in weather and engineering conversions alike.

Frequently asked questions

What is the quick mental conversion?
Subtract 30 and halve. 70 °F becomes about 20 °C against the true 21.1; 90 °F becomes 30 against 32.2. Good enough for weather, and it errs on the cool side, which is the safer direction for a forecast.
What are the oven temperatures?
350 °F is 177 °C, usually written as 180. 375 °F is 190, 400 °F is 200, 425 °F is 220. Recipes round to the nearest convenient mark because domestic ovens are not accurate to a single degree anyway.
Why subtract before dividing?
Because the offset applies to the scale, not to the size of a degree. Dividing first would scale the 32-degree gap between the zeros as well, giving an answer that is wrong everywhere except at one point.
What is a fever in Celsius?
Above about 38 °C, which is 100.4 °F — the threshold most health services use. Normal is often quoted as 98.6 °F or 37 °C, but that figure comes from a rounded nineteenth-century average and modern readings run slightly lower.

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