Convert Kelvin to Celsius
Kelvin to Celsius turns a scientific absolute-temperature reading into the everyday scale most people actually think in. Like all Kelvin conversions, it's a pure offset — subtract a fixed number, with no multiplying required.
Kelvin to Celsius conversion table
| Kelvin (K) | Celsius (°C) |
|---|---|
| 1 | -272.15 |
| 2 | -271.15 |
| 3 | -270.15 |
| 5 | -268.15 |
| 10 | -263.15 |
| 20 | -253.15 |
| 50 | -223.15 |
| 100 | -173.15 |
| 500 | 226.85 |
| 1,000 | 726.85 |
The formula
To convert Kelvin to Celsius, subtract 273.15:
°C = K − 273.15
There's no scaling factor because a kelvin and a Celsius degree measure the exact same size of temperature change — the two scales just start counting from different zeros. Kelvin starts at absolute zero; Celsius starts at water's freezing point, which sits 273.15 kelvin higher.
Worked example: Convert a lab reading of 100 K to Celsius:
100 − 273.15 = −173.15°C
For comparison, 0 K works out to −273.15°C (absolute zero), and 37 K works out to −236.15°C.
This conversion comes up whenever a scientific instrument, dataset, or formula reports temperature in Kelvin and you need a number that matches a household thermometer or weather report.
Frequently asked questions
What is the Kelvin to Celsius formula?
Subtract 273.15: °C = K − 273.15. A kelvin and a Celsius degree are the same size, so the only adjustment needed is for where each scale starts counting from zero.
What is 300 K in Celsius?
26.85°C, a comfortable room temperature. You can check it against the anchor points: 273.15 K = 0°C (freezing) and 373.15 K = 100°C (boiling), so 300 K should land not far above freezing — which it does.
What is 0 K in Celsius?
−273.15°C — absolute zero, the coldest temperature that can exist. Nothing can be colder, which is exactly why Kelvin uses 0 as its starting point instead of an arbitrary one like water's freezing point.