How do I convert kelvin to Celsius?
Type a value in either box, and the answer shows it in the other unit as you type.
- Degrees Celsius (°C)
- 26.85
300 K = 26.85 °C.
Degrees Celsius (°C): 26.85. 300 K = 26.85 °C.
Degrees Celsius (°C) by kelvins (K)
How to calculate
Converts kelvins (K) to degrees Celsius (°C) and back, with the exact unit definitions.
Example with the default inputs (Kelvins (K) 300): 300 K = 26.85 °C.
Formula: °C = K − 273.15
- A kelvin and a degree Celsius are the same size; the scales differ only in their zero: 0 K is −273.15 °C.
- Nothing is colder than absolute zero (0 K, −273.15 °C, −459.67 °F), so a value below it gives no answer.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up; an answer of 1 billion or more shows at most 15 significant digits.
Worked examples
Each example is checked against the calculator on every build.
- Kelvins (K) 0 gives Degrees Celsius (°C) -273.15.Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8
- Kelvins (K) 300 gives Degrees Celsius (°C) 26.85.Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8
- Degrees Celsius (°C) 26.85 gives Kelvins (K) 300.Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8
Other questions people ask
What is the formula to convert kelvin to Celsius?
°C = K − 273.15. For example, 300 K is 26.85 °C.
How do I convert kelvin to Celsius?
Use °C = K − 273.15. 300 K gives 26.85 °C.
How do I convert Celsius back to kelvin?
Reverse the formula, or type the degrees Celsius into the second box and the converter works it out.
What is absolute zero?
0 K, the coldest possible temperature: −273.15 °C, or −459.67 °F. The kelvin scale starts there, so a temperature in kelvin is never negative, and the converter gives no answer below it.
Is it "degrees kelvin"?
No. The unit is the kelvin, written with the symbol K and no degree sign, as in 300 K; NIST SP 811 writes T0 = 273.15 K. Celsius keeps the degree sign: 26.85 °C.