Convert Fahrenheit to Kelvin
To convert degrees Fahrenheit to kelvins, use K = °F × 0.5555555556 + 255.3722222: 68 °F = 293.15 K, and 0 °F = 255.3722222 K.
1 °F = 255.9277778 K
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk Fahrenheit to Kelvin converter to paste a column from Excel.
How to Convert Fahrenheit to Kelvin
- 1 °F = 255.9277778 K
- 1 K = -457.87 °F
- Example: convert 68 °F to K: 68 °F = (68 × 0.5555555556 + 255.3722222) K = 293.15 K
Formula
K = °F × 0.5555555555556 + 255.3722222222
Derivation from SI units:
- T(K) = (t(°F) + 459.67) × 5/9; t(°F) = t(°C) × 9/5 + 32
- SI base unit, fixed by the Boltzmann constant k = 1.380649 × 10⁻²³ J/K
- Solving for K: K = °F × 0.5555555555556 + 255.3722222222
Both units are defined exactly, so the factor is exact. Fahrenheit definition: degree Fahrenheit; Kelvin definition: kelvin.
Worked examples
- The standard-air temperature of 68 °F is 293.15 K.
68 × 0.5555555556 + 255.3722222 = 293.15 K - Water freezes at 32 °F, which is 273.15 K.
32 × 0.5555555556 + 255.3722222 = 273.15 K
Fahrenheit to Kelvin conversion table
| Fahrenheit (°F) | Kelvin (K) |
|---|---|
| -459.67 °F | 0 K |
| -40 °F | 233.15 K |
| -20 °F | 244.2611111 K |
| 0 °F | 255.3722222 K |
| 10 °F | 260.9277778 K |
| 20 °F | 266.4833333 K |
| 32 °F | 273.15 K |
| 40 °F | 277.5944444 K |
| 50 °F | 283.15 K |
| 60 °F | 288.7055556 K |
| 65 °F | 291.4833333 K |
| 68 °F | 293.15 K |
| 70 °F | 294.2611111 K |
| 72 °F | 295.3722222 K |
| 75 °F | 297.0388889 K |
| 80 °F | 299.8166667 K |
| 90 °F | 305.3722222 K |
| 98.6 °F | 310.15 K |
| 100 °F | 310.9277778 K |
| 120 °F | 322.0388889 K |
| 150 °F | 338.7055556 K |
| 180 °F | 355.3722222 K |
| 212 °F | 373.15 K |
| 250 °F | 394.2611111 K |
| 300 °F | 422.0388889 K |
| 350 °F | 449.8166667 K |
| 400 °F | 477.5944444 K |
| 450 °F | 505.3722222 K |
| 500 °F | 533.15 K |
Where it's used
US engineering data in Fahrenheit is converted to kelvin for SI thermodynamic and gas-law calculations.
Fahrenheit to other temperature units
| Conversion | 1 °F equals |
|---|---|
| Fahrenheit to Celsius | -17.22222222 °C |
| Fahrenheit to Kelvin | 255.9277778 K |
| Fahrenheit to Rankine | 460.67 °R |
Frequently asked questions
What is the formula for °F to K?
K = (°F + 459.67) × 5/9. For example, 70 °F = 294.261 K.
What is the formula for degrees Fahrenheit to kelvins?
K = °F × 0.5555555556 + 255.3722222. For example, 68 °F = 293.15 K.
What is 0 °F in K?
0 °F = 255.3722222 K, and 100 °F = 310.9277778 K.
How do I convert a temperature difference from °F to K?
For a difference (an interval), ignore the offset and multiply by 0.5555555556 only: a change of 10 °F is a change of 5.555555556 K.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "degree Fahrenheit (°F)".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1, base unit definitions.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Fahrenheit to Kelvin. Retrieved October 17, 2026, from https://scientificconverters.com/temperature/fahrenheit-to-kelvin/
IEEE
Scientific Converters, "Convert Fahrenheit to Kelvin," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/temperature/fahrenheit-to-kelvin/