Calculator
Fahrenheit to Celsius Calculator
Convert Fahrenheit to Celsius for weather, cooking, appliance settings, science classes, and international temperature comparisons.
Result
- Celsius
- 20
Fahrenheit minus 32, then multiplied by 5/9.
How Fahrenheit to Celsius conversion works
Fahrenheit and Celsius have different zero points and degree sizes, so temperature conversion requires both subtraction and multiplication.
The calculator subtracts 32 from the Fahrenheit value, then multiplies the result by 5/9.
Use Celsius for metric weather reports, science contexts, and many international appliance or cooking references.
Useful next steps
- Convert Celsius to Fahrenheit when your starting value is Celsius.
- Conversion calculators Browse the length, weight, temperature, volume, area, time, data, speed, and cooking conversion hub.
Fahrenheit to Celsius formula
Celsius = (Fahrenheit - 32) * 5 / 9Subtract 32 first, then multiply by 5/9.
- Fahrenheit is the starting temperature.
- 32 adjusts for the difference between the two temperature scales.
- 5/9 adjusts for the different degree sizes.
What the Numbers Mean
- Fahrenheit
- A temperature scale used commonly in the United States.
- Celsius
- A metric temperature scale used in most countries and many scientific contexts.
- Scale offset
- The formulas include 32 because the scales do not share the same zero point.
Assumptions
- Negative temperatures are allowed because temperature scales can go below zero.
- The formula converts temperature, not temperature differences. A temperature difference uses only the 5/9 factor.
- Rounded results can differ slightly from full-precision conversions.
- For cooking, match the rounding convention used by the recipe or appliance.
Worked Examples
32 F to Celsius
- Input
- 32 F
- Formula
- (32 - 32) * 5 / 9
- Output
- 0 C
Water freezes at 32 F, which is 0 C.
68 F to Celsius
- Input
- 68 F
- Formula
- (68 - 32) * 5 / 9
- Output
- 20 C
68 F is a common room-temperature reference.
98.6 F to Celsius
- Input
- 98.6 F
- Formula
- (98.6 - 32) * 5 / 9
- Output
- 37 C
98.6 F is approximately 37 C.
212 F to Celsius
- Input
- 212 F
- Formula
- (212 - 32) * 5 / 9
- Output
- 100 C
Water boils at 212 F, which is 100 C at standard pressure.
Common Fahrenheit to Celsius Reference Values
These benchmarks cover freezing, cool weather, room temperature, body temperature, hot weather, and boiling water.
| Example | Celsius | Common benchmark |
|---|---|---|
| 32 F | 0 C | Freezing point of water |
| 50 F | 10 C | Cool weather |
| 68 F | 20 C | Room temperature reference |
| 98.6 F | 37 C | Typical body-temperature reference |
| 100 F | 37.78 C | Hot weather or fever reference |
| 212 F | 100 C | Boiling point of water at standard pressure |
The exact formula is C = (F - 32) * 5/9. Results are often rounded because many everyday uses do not need long decimals.
Practical Fahrenheit to Celsius Examples
Temperature conversion needs both an offset and a scale change, which is why the formula is not simple multiplication.
Weather report
77 F outside
25 C
This is a common warm-weather conversion for international forecasts.
Room setting
70 F thermostat
21.11 C
Thermostats and appliance settings are often rounded to the nearest whole degree.
Cooking reference
350 F oven
176.67 C
Recipes often round this to 175 C or 180 C depending on the oven scale.
Related Temperature and Unit Conversions
Use the reverse calculator for Celsius-first inputs or move to other common U.S.-to-metric conversions.
Frequently Asked Questions
How do I convert Fahrenheit to Celsius?
Subtract 32 from Fahrenheit, then multiply by 5/9. For example, 77 F equals 25 C.
What is 68 F in Celsius?
68 F equals 20 C.
Why is the formula not just multiplication?
Fahrenheit and Celsius have different zero points, so the formula must adjust by 32 before scaling.
Can this calculator handle negative temperatures?
Yes. Negative Fahrenheit and Celsius values are valid temperatures.
Is this formula exact?
Yes. The formula is exact, but the displayed result may be rounded.
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Disclaimer
This calculator converts temperature scale values and does not account for appliance calibration, altitude, or measurement error.