Fahrenheit to Kelvin Converter
To convert Fahrenheit to kelvin, add 459.67 and multiply by 5/9. The freezing point of water, 32 °F, is 273.15 K.
How to Convert Fahrenheit to Kelvin
To convert degrees Fahrenheit to kelvin, add 459.67, then multiply by 5/9.
For example: 75 °F + 459.67 = 534.67, and 534.67 × 5/9 = 297.039 K.
Where This Comes Up
American lab notebooks, HVAC data sheets and older engineering tables record Fahrenheit, while any thermodynamic calculation needs an absolute scale. This conversion goes straight there without stopping at Celsius.
A 70 °F room is 294.261 K, the figure an ideal-gas calculation would use.
What People Get Wrong
The absolute scale that pairs with Fahrenheit degrees is Rankine, not kelvin: 0 °F is 459.67 °R but 255.372 K. Mixing up the two gives answers that are off by a factor of 1.8.
Fahrenheit to Kelvin Conversion Table
| Degrees Fahrenheit (°F) | Kelvin (K) |
|---|---|
| -459.67 | 0 |
| -100 | 199.817 |
| -40 | 233.15 |
| 0 | 255.372 |
| 32 | 273.15 |
| 50 | 283.15 |
| 70 | 294.261 |
| 98.6 | 310.15 |
| 100 | 310.928 |
| 150 | 338.706 |
| 212 | 373.15 |
| 300 | 422.039 |
| 350 | 449.817 |
| 500 | 533.15 |
| 1,000 | 810.928 |
About These Units
The degree Fahrenheit
On the Fahrenheit scale water freezes at 32 degrees and boils at 212 degrees, so one Fahrenheit degree is 5/9 the size of a Celsius degree. It remains the standard scale for weather, ovens and body temperature in the United States.
The kelvin
The kelvin is the SI base unit of temperature and starts at absolute zero, the point where thermal motion stops. A change of 1 kelvin is exactly the same size as a change of 1 degree Celsius, and kelvin is written without a degree sign.
Definitions follow The SI Brochure, BIPM. See how we calculate for the exact values and rounding rules.
Frequently Asked Questions
What is the formula for Fahrenheit to kelvin?
Kelvin equals (Fahrenheit plus 459.67) times 5/9. For 100 °F that is 559.67 times 5/9, or 310.928 K.
What is absolute zero in Fahrenheit?
Absolute zero is -459.67 °F, which is 0 K.
Why 459.67?
It is the number of Fahrenheit degrees between absolute zero and the Fahrenheit zero point. Adding it puts the reading on an absolute scale before the 5/9 converts the degree size.
Can I convert through Celsius instead?
Yes, and you get the same answer: subtract 32, multiply by 5/9, then add 273.15.