Convert Fahrenheit to Kelvin
Convert Fahrenheit to Kelvin instantly. Formula, worked examples and a full reference table from -40° upward.
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Converting Fahrenheit to Kelvin is not a simple multiplication, because the two scales have different zero points as well as different degree sizes. The conversion needs both a scaling step and an offset.
Enter any temperature above and the result updates as you type. The formula and a reference table covering everyday temperatures follow below.
Fahrenheit to Kelvin formula
To go the other way, use °F = (K − 273.15) × 9/5 + 32.
About these units
Fahrenheit puts water's freezing and boiling points at 32 and 212, giving 180 degrees between them. A Fahrenheit degree is therefore smaller than a Celsius one.
Kelvin starts at absolute zero, the point where thermal motion stops. It uses Celsius-sized degrees and takes no degree symbol.
Fahrenheit to Kelvin conversion table
| Fahrenheit | Kelvin |
|---|---|
| -40 °F | 233.15 K |
| -20 °F | 244.2611 K |
| -10 °F | 249.8167 K |
| 0 °F | 255.3722 K |
| 10 °F | 260.9278 K |
| 20 °F | 266.4833 K |
| 25 °F | 269.2611 K |
| 30 °F | 272.0389 K |
| 37 °F | 275.9278 K |
| 40 °F | 277.5944 K |
| 50 °F | 283.15 K |
| 100 °F | 310.9278 K |
Frequently asked questions
How many kelvins are in a fahrenheit? +
Temperature scales cannot be compared this way, because they do not share a zero point. Use the formula K = (°F − 32) × 5/9 + 273.15 instead.
What is 25 °F in K? +
25 °F equals 269.2611 K. Apply the formula K = (°F − 32) × 5/9 + 273.15.
How do I convert kelvin back to fahrenheit? +
Use °F = (K − 273.15) × 9/5 + 32. The converter above handles both directions, or see our dedicated Kelvin to Fahrenheit page.