Kelvin to Celsius Converter
Two-way converter: change Kelvin to Celsius or Celsius to Kelvin in one step.
Type a value in either field for an instant conversion
About converting Kelvin and Celsius
Kelvin is the SI base unit of thermodynamic temperature, used in physics, chemistry, and astronomy. Celsius is the everyday scale for weather and cooking. Converting Kelvin to Celsius is needed when working with lab data, materials specs, or scientific literature in a human-friendly form.
To convert Kelvin to Celsius, use the formula: °C = K − 273.15. The reverse formula handles the other direction automatically — type into either field.
Every calculation runs locally in your browser and updates instantly — nothing is uploaded, and the result appears the moment you type.
Why use this converter
Works both ways
Convert K to °C or °C to K by typing in either field.
Exact formula
Uses the standard temperature conversion formula with no shortcuts.
No install
Runs in any browser on phone or desktop, with no sign-up required.
Frequently asked questions
How do I convert Kelvin to Celsius?
Subtract 273.15 from the Kelvin value. For example, 300 K = 300 − 273.15 = 26.85 °C.
What is room temperature in Kelvin?
Around 293–298 K (20–25 °C) is the usual room temperature range.
Can Kelvin be negative?
No. Kelvin starts at absolute zero (0 K), which is the lowest possible temperature. Negative Kelvin values are not physical.
What is 100 K in Celsius?
100 K equals −173.15 °C — extremely cold, comparable to liquid nitrogen territory (which is 77 K).
Why subtract 273.15 and not 273?
The exact offset between the scales is 273.15, fixed by the SI definition. Rounding to 273 is fine for rough estimates but introduces a small error.