Unit converter
Fahrenheit to Kelvin Converter
Move a Fahrenheit temperature straight into kelvin, the absolute SI unit. This crops up when an American instrument or dataset reports in Fahrenheit but a physics or chemistry calculation needs absolute temperature, where zero means absolute zero rather than the freezing point of water. It also appears in engineering work that mixes US-sourced readings with SI formulas. Enter a value in degrees Fahrenheit and the tool returns kelvin, with a table of the points people convert most. Use it for lab work fed by Fahrenheit sensors, coursework, or any sum that demands an absolute temperature.
Common Fahrenheit to Kelvin values
| Fahrenheit | Kelvin |
|---|---|
| 0 °F | 255.37 K |
| 32 °F | 273.15 K |
| 50 °F | 283.15 K |
| 68 °F | 293.15 K |
| 98.6 °F | 310.15 K |
| 100 °F | 310.93 K |
| 212 °F | 373.15 K |
How to convert
- Take the temperature in degrees Fahrenheit.
- Subtract 32 to remove the offset, since Fahrenheit puts freezing water at 32 rather than zero.
- Multiply the remainder by 5/9 to convert the degree size to Celsius units.
- Add 273.15 to shift that Celsius value onto the absolute kelvin scale.
- In short, you convert Fahrenheit to Celsius, then Celsius to kelvin, in one combined step.
K = (°F - 32) × 5/9 + 273.15
This combines two affine moves. First the Fahrenheit reading is turned into Celsius by stripping the 32-degree offset and shrinking by 5/9, because a Fahrenheit degree is smaller. Then 273.15 is added to slide that Celsius figure onto the kelvin scale, whose zero sits at absolute zero. The order matters: the subtraction precedes the scaling, and the offset comes last.
- °F
- the temperature in degrees Fahrenheit you start with
- 32
- the Fahrenheit reading at which water freezes
- 5/9
- the ratio of a Celsius degree to a Fahrenheit degree
- 273.15
- the offset that raises a Celsius value to kelvin
Worked example
A reading of 98.6°F from a clinical thermometer is (98.6 - 32) × 5/9, which is 37°C, then plus 273.15, giving 310.15 K. Freezing 32°F becomes (32 - 32) × 5/9 + 273.15, exactly 273.15 K.
Key facts
- Water freezes at 32°F, which equals 273.15 K.
- Water boils at 212°F, equal to 373.15 K.
- Absolute zero is 0 K, the same as -459.67°F.
- A 98.6°F body temperature corresponds to 310.15 K.
Tips
- Convert to Celsius first if it helps you keep the steps straight, then add 273.15 at the very end.
- Hold the full precision through the calculation and round only the final kelvin figure to avoid drift.
Frequently asked questions
What is 32°F in kelvin?+
32°F is the freezing point of water, which on the absolute scale is 273.15 K.
Why are there two steps in the formula?+
Fahrenheit differs from kelvin in both degree size and zero point, so you correct the offset and the scaling, then add the 273.15 that lifts the value to absolute temperature.
What is 212°F in kelvin?+
Boiling water at 212°F converts to (212 - 32) × 5/9 + 273.15, which is 373.15 K.
Is the result written with a degree symbol?+
No. Kelvin is written as a bare number followed by K, with no degree sign, for example 300 K.
Things to watch
- Do not add 273.15 before handling the Fahrenheit offset and scaling; doing the steps out of order gives a wrong answer.
- Kelvin uses no degree symbol, so record the result as a plain number with K.
Sources
Last updated: 2026-01-01
Conversions use internationally defined factors. Provided for general use; verify critical measurements independently.