Fahrenheit to Kelvin formula
K = (°F − 32) × 5⁄9 + 273.15 Example: (98.6°F − 32) × 5⁄9 + 273.15 = 37 + 273.15 = 310.15K How the conversion works
Converting Fahrenheit directly to Kelvin requires bridging two completely different systems, which happens in three distinct steps:
- Step 1: Remove the baseline offset. First, subtract 32 from the Fahrenheit temperature. This removes Fahrenheit's offset so the value aligns with the Celsius scale, where water freezes at 0°C.
- Step 2: Rescale the temperature. Multiply by 5⁄9 because one Fahrenheit degree represents a smaller temperature interval than one Celsius or Kelvin unit.
- Step 3: Shift to the Kelvin scale. Finally, add 273.15. This converts the Celsius value to Kelvin, whose zero point is absolute zero—the lowest temperature physically possible.
About the Fahrenheit scale
Introduced by Daniel Gabriel Fahrenheit in 1724, this scale was a historic breakthrough in standardizing scientific instrumentation. It centers its metrics around localized points, placing the freezing point of water at 32°F and the boiling point at 212°F under standard atmospheric pressure. While it has been widely replaced by the metric system globally, it is still used every day throughout the United States.
About the Kelvin scale
The Kelvin scale is an absolute, thermodynamic scale designed specifically for calculations in physics, astrophysics, and chemistry. Created by William Thomson (Lord Kelvin) in 1848, it sets its zero milestone (0K) at absolute zero—the precise thermal state where all physical molecular motion ceases. Because it lacks negative values entirely, it serves as an essential framework for complex scientific equations.
Reference table
| Fahrenheit | Kelvin |
|---|---|
| −459.67°F | 0K (absolute zero) |
| 32°F | 273.15K (freezing) |
| 68°F | 293.15K (room temperature) |
| 98.6°F | 310.15K (body temperature) |
| 212°F | 373.15K (boiling) |
Frequently asked questions
What is absolute zero in Fahrenheit?
Absolute zero, 0 Kelvin, is −459.67°F. It is the coldest temperature theoretically possible — the point at which particles have minimum thermal motion. This calculator will not let you enter a colder value, since none exists.
Is there a simpler way to think about Kelvin?
Kelvin uses the same size "degree" as Celsius, just starting from absolute zero instead of water's freezing point — so a change of 1K equals a change of 1°C, but never has a negative sign or the word "degrees" (it is just "kelvin," not "degrees Kelvin").
Why does science use Kelvin instead of Celsius or Fahrenheit?
Kelvin has no negative numbers for any real physical temperature, which makes formulas involving gas laws, thermodynamics, and radiation far simpler — you can multiply and divide temperatures directly without the offset that Celsius and Fahrenheit require.
Need the reverse direction? See Kelvin to Fahrenheit.