Temperature conversion
-40 °F to °C
-40 °C
-40 degrees Fahrenheit = -40 degrees Celsius. Exact factor: °C = (°F − 32) × 5/9.
Live converter
Edit either field — the other updates instantly. Type decimal values like 38.4.
The formula
°C = (°F − 32) × 5/9
Worked example: (-40 − 32) × 5/9 = -40 °C.
Values near -40 °F
| °F | °C |
|---|---|
| -43 | -41.67 |
| -42 | -41.11 |
| -41 | -40.56 |
| -40this page | -40 |
| -39 | -39.44 |
| -38 | -38.89 |
| -37 | -38.33 |
Frequently asked
How do you convert degrees Fahrenheit to degrees Celsius?
Apply the formula °C = (°F − 32) × 5/9. Enter any value in the live converter above and the result updates as you type.
What is -40 °F in °C?
-40 °F equals -40 °C. The reference table below shows the values immediately around -40 °F.
Why does temperature conversion add 32?
The two scales have different zero points and step sizes. Water freezes at 32 °F but 0 °C, so the formula rescales by 5/9 and shifts by the 32-degree offset.