ExactConverter

Temperature conversion

-40 °C to °F

-40 °F

-40 degrees Celsius = -40 degrees Fahrenheit. Exact factor: °F = °C × 9/5 + 32.

Live converter

Edit either field — the other updates instantly. Type decimal values like 38.4.

The formula

°F = °C × 9/5 + 32

Worked example: -40 × 9/5 + 32 = -40 °F.

Values near -40 °C

°C °F
-43 -45.4
-42 -43.6
-41 -41.8
-40this page -40
-39 -38.2
-38 -36.4
-37 -34.6

Frequently asked

How do you convert degrees Celsius to degrees Fahrenheit?

Apply the formula °F = °C × 9/5 + 32. Enter any value in the live converter above and the result updates as you type.

What is -40 °C in °F?

-40 °C equals -40 °F. The reference table below shows the values immediately around -40 °C.

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.