Kelvin to Fahrenheit

Kelvins and degrees Fahrenheit

The kelvin is the SI base unit of thermodynamic temperature, starting at absolute zero; since 2019 it is defined by fixing the Boltzmann constant. Science and engineering use kelvins, as do color temperatures of light bulbs and screens (2700 K warm, 6500 K daylight).

The Fahrenheit scale puts water's freezing point at 32 °F and boiling at 212 °F; one Fahrenheit degree is 5/9 of a Celsius degree. The United States and a few Caribbean countries use Fahrenheit for weather, ovens and body temperature.

Worked example

Convert 300 K with °F = (K − 273.15) × 9/5 + 32: the result is 80.33 °F. Likewise 293.15 K = 68 °F.

Estimating in your head

Go through Celsius: subtract 273.15, multiply by 1.8, then add 32. 300 K → 26.85 °C → 80.33 °F.

Going the other way

To convert degrees Fahrenheit to kelvins, type in the right-hand box; the page solves the same formula backwards. The swap button between the boxes opens the reverse page.

°F = (K − 273.15) × 9/5 + 32

Temperature scales have different zero points as well as different degree sizes, so the conversion scales and shifts; there is no single factor. The page converts through kelvin using the exact definitions in NIST SP 811. Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.