Temperature conversion
Fahrenheit to Celsius (°F to °C)
Convert Fahrenheit to Celsius using C = (F − 32) × 5/9.
Fahrenheit to Celsius conversion chart
| Fahrenheit | Celsius |
|---|---|
| -40 °F | -40 °C |
| 0 °F | -17.7778 °C |
| 20 °F | -6.6667 °C |
| 32 °F | 0 °C |
| 40 °F | 4.4444 °C |
| 50 °F | 10 °C |
| 60 °F | 15.5556 °C |
| 70 °F | 21.1111 °C |
| 80 °F | 26.6667 °C |
| 90 °F | 32.2222 °C |
| 98.6 °F | 37 °C |
| 100 °F | 37.7778 °C |
| 200 °F | 93.3333 °C |
| 350 °F | 176.667 °C |
How to convert by hand
C = (F − 32) × 5/9
Temperature scales have different zero points, so you cannot simply multiply — the offset has to be applied as well. That is why °F and °C do not scale proportionally.
Worked example: 90 °F × the formula above = 32.2222 °C .
Related conversions
About Fahrenheit and Celsius
Temperature is the one conversion that is not a simple multiplication: the scales start at different points, so an offset applies as well as a ratio.
Fahrenheit
US customaryWater freezes at 32° and boils at 212°, giving 180 degrees between the two.
Commonly used for: Weather, cooking and body temperature in the United States.
Celsius
Metric (SI derived)Zero at the freezing point of water, 100 at its boiling point at sea level.
Commonly used for: Weather and cooking in most of the world.
Questions
How do you convert Fahrenheit to Celsius?
Use the formula C = (F − 32) × 5/9. For example, 70°F becomes 21.1111°C.
What is 40 °F in °C?
40°F = 4.4444 °C. Type any value into the converter above to get an exact answer.
How do I convert Celsius back to Fahrenheit?
Use our Celsius to Fahrenheit converter, which applies the inverse formula.
Is this converter accurate?
Yes. Linear conversions use the internationally agreed factors published by NIST (SP 811), and temperature conversions use the exact defining formulas. Calculations run at full double precision and are only rounded for display.
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