Convert Kelvin to Celsius
Celsius = Kelvin − 273.15. Type any temperature below to convert kelvin to celsius both ways — it runs entirely in your browser.
Kelvin to Celsius formula
Temperature scales have different zero points, so the conversion is a multiply-and-add, not a single ratio:
Celsius = Kelvin − 273.15
To go the other way, Kelvin = Celsius + 273.15.
Worked example
Convert 300 K to celsius:
= 300 − 273.15 = 26.85 °C.
Common temperatures in Kelvin and Celsius
| Reference point | Kelvin (K) | Celsius (°C) |
|---|---|---|
| Absolute zero | 0 | -273.15 |
| Freezing point of water | 273.15 | 0 |
| Refrigerator | 277.15 | 4 |
| Room temperature | 294.15 | 21 |
| Normal human body temperature | 310.15 | 37 |
| A hot summer day | 318.15 | 45 |
| Boiling point of water (sea level) | 373.15 | 100 |
About the Kelvin and Celsius scales
Kelvin: The kelvin is the SI base unit of temperature. It starts at absolute zero (0 K = −273.15 °C) and uses the same degree size as Celsius, so it is written without a degree sign.
Celsius: Celsius (centigrade) puts 0° at the freezing point of water and 100° at its boiling point at sea level. It is the everyday temperature scale used almost everywhere outside the United States.
Frequently asked questions
- What is 300 K in Celsius?
- 300 K = 26.85 °C.
- How do I convert Kelvin to Celsius?
- Use celsius = kelvin − 273.15. For example, 300 K → 26.85 °C.
- How do I convert Celsius back to Kelvin?
- Reverse it: kelvin = celsius + 273.15.
- Why isn't converting Kelvin to Celsius just multiplication?
- Because the two scales start their zero at different temperatures, so after scaling by 1 you also subtract 273.15. Skipping that constant is the most common temperature-conversion mistake.