Fahrenheit to Kelvin Calculator
Enter fahrenheit to find kelvin. (°F - 32) * 5 / 9 + 273.15.
How the result changes
Only fahrenheit changes; all other inputs stay at your current values. The line illustrates the formula across the shown range. This is not a forecast of real-world outcomes.
About this calculation
Convert fahrenheit (°F) to kelvin (K) while preserving the underlying temperature quantity. The calculator updates when the input changes and shows the conversion rule and a worked example.
Formula
(°F - 32) * 5 / 9 + 273.15
Worked example
With Fahrenheit: 68 °F, kelvin is 293.15 K.
How to convert fahrenheit to kelvin
Enter a temperature in fahrenheit to report it in kelvin. Apply the displayed formula to account for these scales' zero points and degree sizes. A temperature value and a temperature difference should not be converted the same way.
(°F - 32) * 5 / 9 + 273.15. As a reference point, 32 °F equals 273.15 K with this conversion. This is an example, not a recommended level or target.
What the unit relationship means
Fahrenheit and kelvin are scales for the same temperature reading. Their origins can differ, so the conversion may add or subtract an offset as well as change the size of a degree. This is unlike a simple length or mass factor. The target number is a new label for the same thermal state. A temperature difference, such as a rise of ten degrees, must be handled separately from an absolute thermometer reading because offsets cancel when differences are taken.
Check the direction of the result
A second check uses 64 °F, which becomes 290.927778 K; compare that with 32 °F becoming 273.15 K. The two readings differ by the correct degree-size relationship, but the output numbers need not be twice one another because the scales can have different zero points. Use this two-point check when a result seems surprising: a simple multiplication rule may omit a required offset.
When this conversion is useful
Express the same temperature reading in fahrenheit and kelvin, for example when comparing a forecast, measurement, or equipment specification from different systems.
What to check
These formulas convert temperature readings with their zero points. A temperature difference uses only the degree-size factor, without the zero-point offset. In this direction the entered fahrenheit is reported as kelvin; check both unit symbols when copying a figure from another source, because the reverse direction answers a different question.
Precision and reporting
Thermometers and forecasts commonly round their readings. Converting a rounded temperature can produce decimals that look more precise than the observation. When reporting a result, preserve the relevant temperature scale symbol and round according to the accuracy of the original instrument or forecast. For a separate reporting example, 7.3 °F produces 259.427778 K. If 7.3 °F was an approximate reading, the converted digits should not be treated as a more accurate measurement.
Common questions
What is the reverse of fahrenheit to kelvin?
To return from K to °F, apply the inverse temperature formula, including the zero-point offset. Dividing by a scale factor alone does not reverse a temperature reading.
Inputs
- Fahrenheit (°F)