Convert fahrenheit to kelvin instantly. Enter a value below, or use the formula and reference table further down the page.
In practice
Fahrenheit-to-Kelvin needs the Celsius step first: K = (°F − 32) × 5/9 + 273.15. Subtract 32 before multiplying, a common slip when doing it by hand. Landmarks help check your answer: water freezes at 32°F = 273.15 K, normal body temperature of 98.6°F is 310.15 K, and 212°F boiling is 373.15 K. Absolute zero is −459.67°F. US engineers sometimes use the Rankine scale, which has the same size degree as Fahrenheit but starts at absolute zero (°R = °F + 459.67) — so convert to kelvin by multiplying Rankine by 5/9. Kelvin has no degree sign and cannot go below zero.
How to convert fahrenheit to kelvin
Multiply by 0.5555555556, then add 255.3722.
K = (°F × 0.5555555556) + 255.3722Example: 10 °F = 260.9278 K.
Fahrenheit to Kelvin conversion table
| Fahrenheit (°F) | Kelvin (K) |
|---|---|
| 1 °F | 255.9278 K |
| 2 °F | 256.4833 K |
| 3 °F | 257.0389 K |
| 4 °F | 257.5944 K |
| 5 °F | 258.15 K |
| 10 °F | 260.9278 K |
| 15 °F | 263.7056 K |
| 20 °F | 266.4833 K |
| 25 °F | 269.2611 K |
| 50 °F | 283.15 K |
| 100 °F | 310.9278 K |
Frequently asked questions
How many kelvin is 1 degree Fahrenheit?
1 degree Fahrenheit equals 255.9278 kelvin.
What is the formula to convert °F to K?
To convert °F to K, multiply by 0.5555555556 and add 255.3722. The full formula is: K = (°F × 0.5555555556) + 255.3722.
How do I convert kelvin back to fahrenheit?
Use the same calculator above and type your value into the kelvin field instead — it converts in both directions. Or use the reverse formula: °F = (K − 255.3722) ÷ 0.5555555556.
Is the °F to K conversion exact?
The conversion factor used here (0.5555555556) is the standard internationally defined value. Results on this page are rounded to four decimal places for readability.