Unit Converters
Fahrenheit to Celsius converter.
Type degrees Fahrenheit or Celsius and the other box updates as you type. Negative temperatures work. °C = (°F − 32) ÷ 1.8. Runs in your browser; nothing is sent anywhere.
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Result
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Answer
68 °F is 20 °C. The scales meet at -40: -40 °F = -40 °C.
Formula
°C = (°F − 32) ÷ 1.8
Take 68 °F. °C = (°F − 32) ÷ 1.8 gives 20 °C. Going back: apply the reverse formula to 20 °C to return to 68 °F.
Quick estimate: subtract 30 from the Fahrenheit value and halve it (it drifts at larger values).
Fahrenheit to Celsius table (1 to 100)
| Degrees Fahrenheit (°F) | Degrees Celsius (°C) |
|---|---|
| 1 | -17.22 |
| 2 | -16.67 |
| 3 | -16.11 |
| 4 | -15.56 |
| 5 | -15 |
| 6 | -14.44 |
| 7 | -13.89 |
| 8 | -13.33 |
| 9 | -12.78 |
| 10 | -12.22 |
| 15 | -9.44 |
| 20 | -6.67 |
| 25 | -3.89 |
| 30 | -1.11 |
| 40 | 4.44 |
| 50 | 10 |
| 60 | 15.56 |
| 70 | 21.11 |
| 75 | 23.89 |
| 80 | 26.67 |
| 90 | 32.22 |
| 100 | 37.78 |
Examples
- 32 °F = 0 °C
- 68 °F = 20 °C
- 98.6 °F = 37 °C
- 212 °F = 100 °C
Source
Conversion factors and formulas: NIST SP 811, Appendix B.9: t/°C = (t/°F - 32)/1.8; NIST Handbook 44 (2026), Appendix C: temperature conversion table. Retrieved 2026-10. Results are rounded for display to 2 decimal places; the arithmetic itself is not rounded.
FAQ
What is the formula to convert degrees Fahrenheit to degrees Celsius?
°C = (°F − 32) ÷ 1.8. For 68 °F that gives 20 °C.
What is 98.6 °F in degrees Celsius?
98.6 °F is 37 °C.
Can I convert negative temperatures?
Yes. The same formula works below zero. For example -10 °F is -23.33 °C. Both scales read -40 at the same point.
Is there a quick way to estimate it?
Quick estimate: subtract 30 from the Fahrenheit value and halve it (it drifts at larger values). Use the exact formula when accuracy matters.
Where do the numbers come from?
The formula is published in NIST Special Publication 811, Appendix B.9, and in NIST Handbook 44, Appendix C. Sources are listed on this page.
Disclaimer
Informational arithmetic using the published factors above. For legal-for-trade, engineering or medical use, check against the governing standard.