Skip to content
UnitCalculators.com

Degrees Fahrenheit to kelvins

To convert degrees Fahrenheit to kelvins, use the formula K = (°F − 32) × 5/9 + 273.15.

K = (°F − 32) × 5/9 + 273.15NIST HB 44 · BIPM SI
°F
295.3722K

72 °F = 295.3722 K

How to convert degrees Fahrenheit to kelvins

The kelvin is the SI base unit of temperature, fixed since 2019 by defining the Boltzmann constant as exactly 1.380649×10⁻²³ J/K — 0 K is absolute zero. The degree Fahrenheit is the Fahrenheit scale, °F = °C × 9/5 + 32 — water freezes at 32 °F and boils at 212 °F.

Worked example — 72 °F converts to 295.3722 K using K = (°F − 32) × 5/9 + 273.15.

Degrees Fahrenheit to kelvins table

Common conversions. The reverse table is on kelvins to degrees Fahrenheit.
Degrees FahrenheitKelvins
-40 °F233.15 K
0 °F255.3722 K
32 °F273.15 K
72 °F295.3722 K
98.6 °F310.15 K
212 °F373.15 K

Reverse and related

About degrees Fahrenheit and kelvins

Degree Fahrenheit (°F)

Definition. The Fahrenheit scale, °F = °C × 9/5 + 32 — water freezes at 32 °F and boils at 212 °F

History and origin

The Fahrenheit scale was devised by the physicist Daniel Gabriel Fahrenheit in 1724, using a brine freezing point and human body temperature to set its reference points. It places the freezing point of water at 32 degrees and the boiling point at 212.

Current use

Fahrenheit is used mainly in the United States and a few nearby territories for weather, cooking and body temperature, while most of the world uses Celsius.

Source: NIST Handbook 44, Appendix C, Conversion Equations for Units of Temperature

Kelvin (K)

Definition. The SI base unit of temperature, fixed since 2019 by defining the Boltzmann constant as exactly 1.380649×10⁻²³ J/K — 0 K is absolute zero

History and origin

The kelvin is named after William Thomson, Lord Kelvin, who proposed an absolute temperature scale in 1848 starting from absolute zero. Since 2019 it has been defined by fixing the Boltzmann constant, tying temperature directly to energy.

Current use

The kelvin is the scientific temperature unit used in physics and engineering, and also describes the colour temperature of light sources.

Source: BIPM, The International System of Units (SI), 9th ed. (2019)

Where people use this

Degrees Fahrenheit: weather in the US, oven temperatures, body temperature. Kelvins: science and physics, colour temperature. 32 °F (freezing) is 273.15 K.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
K = (°F − 32) × 5/9 + 273.15

Fahrenheit differs from Kelvin in both step size and starting point: one Fahrenheit degree is 5/9 of a kelvin, and the Fahrenheit freezing point of 32 °F sits at 273.15 K. So the conversion removes 32, rescales by 5/9, then adds 273.15.

Every value is carried to full double precision; the display is rounded.

Sources: BIPM, The International System of Units (SI), 9th ed. (2019); NIST Handbook 44, Appendix C, Conversion Equations for Units of Temperature.

Questions people ask

How do you convert Fahrenheit to Kelvin?

Subtract 32, multiply by 5/9, then add 273.15: K = (°F − 32) × 5/9 + 273.15.

What is 32 °F in Kelvin?

The freezing point of water, 32 °F, is 273.15 K.

What is 98.6 °F in Kelvin?

Body temperature, 98.6 °F, is about 310.15 K.

All degree Fahrenheit conversions