-40° Fahrenheit to Celsius

-40°F = -40°C

Formula: C = (F − 32) × 5/9

Fahrenheit to Celsius Converter

Choose the type of measurement to convert
Select the source unit to convert from
Select the target unit to convert to
Enter a numeric value or fraction to convert
Sig. Figures:

How cold is -40°F?

-40°F (-40°C) is a deep-freezer temperature used for long-term food preservation.

What does -40°F look like?

A deep-freezer temperature used for long-term food preservation
-40°F (-40°C) is a deep-freezer temperature used for long-term food preservation.

-40°F on the Celsius scale

°F-60-40-2002040°C-50-40-30-20-10010

-40°F = -40°C

Did you know? Celsius equals Fahrenheit is -40°C.

-40 is the only temperature where Celsius and Fahrenheit scales read the same number.

How to Convert Fahrenheit to Celsius

The formula is:

C = (F − 32) × 5/9

Example: -40° Fahrenheit = -40° Celsius

-40°F equals exactly -40°C — the only temperature where both Fahrenheit and Celsius scales read the same number. This extreme cold occurs in Arctic and subarctic regions and parts of interior Canada and Siberia during winter.

About these units

Fahrenheit: The degree Fahrenheit (°F) is a temperature unit in the US customary system. On this scale, the freezing point of water is 32 °F and the boiling point is 212 °F — exactly 180 degrees apart. ...

Celsius: The degree Celsius (°C) is the SI-derived unit of temperature. It is defined so that 0 °C = 273.15 K exactly, with the same unit increment as the kelvin.

Frequently Asked Questions

What is -40°F in Celsius?

-40°F equals -40°C. The formula is: C = (F − 32) × 5/9.

What does -40 degrees Fahrenheit look like in degrees Celsius?

-40°F (-40°C) is an extremely cold temperature below zero Fahrenheit.

How do you calculate -40°F to Celsius?

Use the formula: C = (F − 32) × 5/9. Applying it: -40°F = -40°C.

Share This Calculation

-40 degrees Fahrenheit = -40 degrees Celsius
-40 degrees Fahrenheit = -40 degrees Celsius — conversion chart

Nearby Conversions

-50 degrees Fahrenheit-45.56 degrees Celsius -49 degrees Fahrenheit-45 degrees Celsius -48 degrees Fahrenheit-44.44 degrees Celsius -47 degrees Fahrenheit-43.89 degrees Celsius -46 degrees Fahrenheit-43.33 degrees Celsius -45 degrees Fahrenheit-42.78 degrees Celsius -44 degrees Fahrenheit-42.22 degrees Celsius -43 degrees Fahrenheit-41.67 degrees Celsius -42 degrees Fahrenheit-41.11 degrees Celsius -41 degrees Fahrenheit-40.56 degrees Celsius -39 degrees Fahrenheit-39.44 degrees Celsius -38 degrees Fahrenheit-38.89 degrees Celsius -37 degrees Fahrenheit-38.33 degrees Celsius -36 degrees Fahrenheit-37.78 degrees Celsius -35 degrees Fahrenheit-37.22 degrees Celsius -34 degrees Fahrenheit-36.67 degrees Celsius -33 degrees Fahrenheit-36.11 degrees Celsius -32 degrees Fahrenheit-35.56 degrees Celsius -31 degrees Fahrenheit-35 degrees Celsius -30 degrees Fahrenheit-34.44 degrees Celsius

Temperature conversion chart

To Fahrenheit To Celsius To Kelvin
From Fahrenheit (F) F (F - 32) × 5/9 (F - 32) × 5/9 + 273.15
From Celsius (C or o) (C × 9/5) + 32 C C + 273.15
From Kelvin (K) (K - 273.15) × 9/5 + 32 K - 273.15 K

For general conversions between Fahrenheit and Celsius, see the Fahrenheit to Celsius converter.

Also convert Degrees Fahrenheit to:

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.

Conversion factors verified against NIST, BIPM, ITS-90 (International Temperature Scale) Defined by the absolute thermodynamic scale (Kelvin). Last reviewed: March 2026
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes