Celsius to Kelvin Converter
0 °C = 273.15 K. Absolute zero is 0 K = −273.15 °C. Water boils at 100 °C = 373.15 K at sea level.
Inverse conversion
273.15 K = 0 °C (water freezing point). Absolute zero = 0 K = −273.15 °C. Body temp = 310.15 K.
Formula
Formula
K = °C + 273.15
Worked example
To convert 100°C (boiling point of water at sea level) to Kelvin: 100 + 273.15 = 373.15 K.
Quick reference table
| °C | K |
|---|---|
| -273.15 | 0 |
| -200 | 73.15 |
| -100 | 173.15 |
| 0 | 273.15 |
| 20 | 293.15 |
| 37 | 310.15 |
| 100 | 373.15 |
| 1000 | 1273.15 |
Unit definitions
Celsius (°C)
Celsius (°C) uses the freezing point of water (0°C) and boiling point (100°C) as reference points at standard pressure.
Kelvin (K)
Kelvin (K) is the SI absolute temperature scale. 0 K = absolute zero (−273.15°C). There are no negative Kelvin values.
Common use cases
- Scientific and physics calculations requiring absolute temperature
- Gas law calculations (PV = nRT)
- Thermodynamics and heat transfer
- Spectroscopy and blackbody radiation