Fahrenheit to Celsius Converter
To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9. 98.6 °F = 37 °C.
Sources: NIST SP 811, BIPM SI Brochure Updated
Result
68 °F = 20 °C
How to convert Fahrenheit to Celsius
°C = (°F − 32) × 5/9
The numbers in the formula are exact. Both scales are defined through the kelvin: a Celsius temperature is the kelvin temperature minus 273.15, and a Fahrenheit degree is 5/9 of a Celsius degree with 32 °F at 0 °C.
Worked example: 98.6 °F
- Start with the temperature in Fahrenheit: 98.6 °F.
- Subtract 32: 98.6 − 32 = 66.6.
- Multiply by 5/9: 66.6 × 5/9 = 37 °C.
Fahrenheit and Celsius side by side
Fahrenheit to Celsius chart
Degrees Fahrenheit from −40 to 500 converted to degrees Celsius with the exact formula, shown to five significant digits.
| °F | °C |
|---|---|
| −40 | −40 |
| −35 | −37.222 |
| −30 | −34.444 |
| −25 | −31.667 |
| −20 | −28.889 |
| −15 | −26.111 |
| −10 | −23.333 |
| −5 | −20.556 |
| 0 | −17.778 |
| 5 | −15 |
| 10 | −12.222 |
| 15 | −9.4444 |
| 20 | −6.6667 |
| 25 | −3.8889 |
| 30 | −1.1111 |
| 35 | 1.6667 |
| 40 | 4.4444 |
| 45 | 7.2222 |
| 50 | 10 |
| 55 | 12.778 |
| 60 | 15.556 |
| 65 | 18.333 |
| 70 | 21.111 |
| 75 | 23.889 |
| °F | °C |
|---|---|
| 80 | 26.667 |
| 85 | 29.444 |
| 90 | 32.222 |
| 95 | 35 |
| 100 | 37.778 |
| 105 | 40.556 |
| 110 | 43.333 |
| 115 | 46.111 |
| 120 | 48.889 |
| 150 | 65.556 |
| 175 | 79.444 |
| 200 | 93.333 |
| 225 | 107.22 |
| 250 | 121.11 |
| 275 | 135 |
| 300 | 148.89 |
| 325 | 162.78 |
| 350 | 176.67 |
| 375 | 190.56 |
| 400 | 204.44 |
| 425 | 218.33 |
| 450 | 232.22 |
| 475 | 246.11 |
| 500 | 260 |
°C = (°F − 32) × 5/9. Factors: NIST SP 811, BIPM SI Brochure. unitcheck.net/temperature/fahrenheit-to-celsius/
Common values
| Fahrenheit | Celsius | What it is |
|---|---|---|
| −459.67 °F | −273.15 °C | absolute zero |
| −40 °F | −40 °C | the only temperature where both scales read the same |
| 0 °F | −17.7778 °C | |
| 32 °F | 0 °C | freezing point of water |
| 68 °F | 20 °C | |
| 98.6 °F | 37 °C | conventional figure for normal body temperature |
| 212 °F | 100 °C | boiling point of water at standard pressure, to the nearest degree |
| 350 °F | 176.667 °C | |
| 400 °F | 204.444 °C | |
| 450 °F | 232.222 °C |
A degree is not the same size on both scales
A change of 1 °F is a change of 5/9 °C (about 0.556 °C). That is why the formula has two steps: subtracting 32 lines up the freezing points, and multiplying by 5/9 rescales the degrees. For a temperature difference, such as “10 °F warmer than yesterday”, skip the 32 and multiply by 5/9 only: 10 °F warmer is about 5.6 °C warmer.
Going the other way? Use the Celsius to Fahrenheit converter.
Frequently asked questions
What is the formula for Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. In words: subtract 32 and multiply by 5/9. Example: 98.6 °F = 37 °C.
At what temperature are Celsius and Fahrenheit equal?
At −40. Put −40 into either formula and the same number comes out: −40 °C = −40 °F. Above that point the Fahrenheit number is always the larger one.
What is 350 °F in Celsius for an oven?
350 °F is 176.7 °C; the nearest common Celsius oven setting is 180 °C. Likewise 400 °F is 204.4 °C (nearest setting 200 °C) and 425 °F is 218.3 °C (220 °C). The chart on this page covers oven temperatures up to 500 °F.
Is there a quick way to estimate it?
Subtract 30 and halve the result. It is exact at 50 °F and within about 1 °C between 32 and 68 °F, but the error grows as you move away: at 212 °F it says 91 °C instead of 100 °C.
Is the conversion exact?
Yes. The factor 9/5 and the offset 32 are exact by definition, so the only rounding is in the number of decimals you display.
Sources
- NIST Special Publication 811, Guide for the Use of the International System of Units, Appendix B.8: Factors for Units Listed Alphabetically — exact factors are printed in bold in the NIST table (checked October 12, 2026)
- BIPM, The International System of Units (SI Brochure), 9th edition — defines the SI units, the prefixes and the units accepted for use with the SI