The two most common temperature scales worldwide, converted with the internationally defined exact relationship between them.
How it works
Subtracting 32 from Fahrenheit and multiplying by 5/9 gives Celsius; multiplying Celsius by 9/5 and adding 32 gives Fahrenheit back.
What this does not include
This does not include Kelvin — for that, use this site’s full temperature converter, which covers all three scales on one page.
How to use this calculator
- Enter a value in either Fahrenheit or Celsius — the other field fills in automatically.
A worked example
98.6°F (commonly cited average body temperature) → (98.6 − 32) × 5/9 = 37°C. −40°F → (−40 − 32) × 5/9 = −40°C, the one point where both scales agree.
What the formula does
| Term | Role |
|---|---|
| − 32 | Removes Fahrenheit’s offset zero point |
| × 5/9 | Scales down to Celsius’s larger degree size |
Edge cases worth knowing
−40 is the single temperature where Fahrenheit and Celsius read the same number — this calculator’s reverse (Celsius to Fahrenheit) page shares the exact same crossing point.
Normal body temperature varies somewhat by individual and time of day — 98.6°F (37°C) is a commonly cited average, not a fixed universal value for every person at every moment.
Frequently asked questions
Is this the same conversion as the site’s celsius-to-fahrenheit calculator?
Yes, functionally identical — this version leads with Fahrenheit first, for anyone specifically searching “fahrenheit to celsius” rather than the reverse.
Why is normal body temperature often quoted as 98.6°F?
It converts to exactly 37°C, a commonly cited average — though normal body temperature varies somewhat by individual and time of day.
What temperature is the same on both scales?
−40 degrees — the one point where Celsius and Fahrenheit numerically coincide.
