Celsius to Kelvin (°C to K)
Convert °C to K — Temperature converter
Also written as C to K.
K = °C + 273.15.
Celsius (°C) and Kelvin (K) use the same-sized degree — a change of 1 °C is a change of 1 K — so converting between them only shifts the zero point. To convert Celsius to Kelvin, add 273.15.
Kelvin starts at absolute zero (0 K = −273.15 °C), the coldest possible temperature, which is why Kelvin has no negative values and is used throughout physics and chemistry. Water freezes at 273.15 K (0 °C) and boils at 373.15 K (100 °C).
1 °C = 274.15 K
Celsius to Kelvin formula
K = °C + 273.15
Worked examples
- 25 °C = 298.15 K
- 100 °C = 373.15 K
Common uses
- Gas-law and thermodynamics calculations
- Reporting scientific temperatures in SI units
- Converting lab readings from °C to K
Celsius to Kelvin conversion table
| Celsius (°C) | Kelvin (K) |
|---|---|
| -40 | 233.15 |
| -20 | 253.15 |
| -10 | 263.15 |
| 0 | 273.15 |
| 10 | 283.15 |
| 20 | 293.15 |
| 25 | 298.15 |
| 30 | 303.15 |
| 37 | 310.15 |
| 40 | 313.15 |
| 50 | 323.15 |
| 75 | 348.15 |
| 100 | 373.15 |
| 180 | 453.15 |
| 200 | 473.15 |
Frequently asked questions
What is the formula to convert Celsius to Kelvin?
K = °C + 273.15. The degree size is identical; only the zero point moves.
What is 0 °C in Kelvin?
0 °C = 273.15 K (the freezing point of water).
What is 25 °C in Kelvin?
25 °C = 298.15 K — a typical room temperature.
What is 100 °C in Kelvin?
100 °C = 373.15 K (the boiling point of water at sea level).