Fahrenheit to Celsius (°F to °C)
Result
-17.22222222 Celsius
Formula
°C = (°F − 32) × 5/9
The kelvin is the SI base unit, defined through the Boltzmann constant. A Celsius temperature is the kelvin temperature minus 273.15, and a Fahrenheit degree is 5/9 of a Celsius degree with water freezing at 32 °F. Rankine uses Fahrenheit-sized degrees from absolute zero.
Worked examples
- 32 °F × 0.5555555556 − 17.77777778 = 0 °C
- 98.6 °F × 0.5555555556 − 17.77777778 = 37 °C
- 212 °F × 0.5555555556 − 17.77777778 = 100 °C
- 350 °F × 0.5555555556 − 17.77777778 = 176.66667 °C
Things to know about °F to °C
- Subtract 32 first, then multiply by 5/9. Doing it the other way round gives the wrong answer.
- The familiar 98.6 °F body temperature is simply 37 °C converted; normal ranges vary by person and by where it is measured.
- A change of 18 °F is a change of 10 °C (divide by 1.8, no −32).
Fahrenheit to Celsius table
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| 1 | -17.222222 |
| 2 | -16.666667 |
| 5 | -15 |
| 10 | -12.222222 |
| 20 | -6.6666667 |
| 32 | 0 |
| 50 | 10 |
| 98.6 | 37 |
| 100 | 37.777778 |
| 212 | 100 |
| 350 | 176.66667 |
| 1,000 | 537.77778 |
The units
- Fahrenheit (°F)
- Fahrenheit: degrees 5/9 the size of Celsius degrees, with water freezing at 32 °F and boiling at 212 °F at sea level.
- Celsius (°C)
- Celsius: the kelvin temperature minus 273.15. Water freezes at about 0 °C and boils at about 100 °C at sea level.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy