Kelvin to Fahrenheit (K to °F)
1 kelvin equals -457.87 degrees Fahrenheit.
How to convert kelvins to degrees Fahrenheit
Converting kelvins to degrees Fahrenheit is not a simple multiplication, so use the formula below.
°F = (K − 273.15) × 9/5 + 32
Example: 10 kelvins = -441.67 degrees Fahrenheit.
Temperature scales have different zero points, so converting is not just multiplication. Differences in degrees convert differently from absolute readings.
About these units
Kelvin (K)
The SI base unit of temperature. Zero kelvin is absolute zero, where particles have minimal thermal motion. A kelvin step is the same size as a Celsius degree.
Lord Kelvin, born William Thomson, published an absolute temperature scale in 1848 and refined it with James Joule in 1854. Its zero sits at absolute zero, and its degree is the same size as a Celsius degree. The kelvin entered the SI in 1954, defined as 1/273.16 of the thermodynamic temperature of the triple point of water, where ice, liquid and vapor coexist. In 1967 the 13th CGPM renamed the unit from the degree Kelvin to simply the kelvin, with symbol K, and no word degree.
Since 20 May 2019 the kelvin has been defined by fixing the Boltzmann constant at exactly 1.380649 times 10 to the minus 23 joule per kelvin, which frees it from the properties of any one substance. Scientists use it for stars and cryogenics, and lighting designers use it for color temperature. NIST notes that incandescent bulbs run near 3,000 K, daylight lamps at 5,000 to 5,600 K, and the Sun's surface at about 5,800 K. Room temperature, about 21 degrees Celsius, is roughly 294 K.
The kelvin is the reference unit for temperature on this site.
Sources: NIST: the kelvin and the SI redefinition; BIPM: 13th CGPM (1967), Resolution 3; Wikipedia: Kelvin
Degree Fahrenheit (°F)
The temperature scale used in the United States and a few other countries: water freezes at 32 °F and boils at 212 °F. Proposed by Daniel Gabriel Fahrenheit in 1724.
Daniel Gabriel Fahrenheit, who lived from 1686 to 1736, proposed his scale in 1724. His zero came from a freezing mixture of ice, water and ammonium chloride (or sea salt), which holds a stable temperature, and his upper reference of about 96 was his estimate of human body temperature. His own letters say he built on Ole Rømer's scale. Accounts of how he picked zero differ, and a popular German story that it was the coldest winter day in his home city of Danzig has failed verification.
Around 1776 to 1777 a Royal Society committee led by Henry Cavendish fixed water's freezing point at 32 degrees and its boiling point at 212, exactly 180 degrees apart, which moved body temperature to about 98.6. Today the scale is defined through the kelvin; NIST puts absolute zero at minus 459.67 degrees Fahrenheit. It remains in everyday use in the United States and its territories, Palau, the Federated States of Micronesia, the Marshall Islands and the Cayman Islands. A comfortable room is around 70 degrees, which is about 21 degrees Celsius.
0 degrees Fahrenheit = 255.3722222 kelvins (approximately).
Sources: Wikipedia: Fahrenheit; NIST: the kelvin and the SI redefinition; NIST Guide to the SI, Appendix B.8: conversion factors
Related conversions
- Fahrenheit to kelvin (reverse)
- Kelvin to Celsius
- Kelvin to Rankine
- Kelvin to Réaumur
- Kelvin to Delisle
- Kelvin to Newton
- Kelvin to Rømer
- Celsius to Fahrenheit
- Rankine to Fahrenheit
- Réaumur to Fahrenheit
- Delisle to Fahrenheit
- Newton to Fahrenheit
- Rømer to Fahrenheit
See all temperature units.