Celsius to Kelvin Converter
Convert degrees Celsius to kelvins instantly — with formula, examples and table.
Enter any number above and the result updates as you type. Everything runs locally in your browser, so it is instant and private.
Formula: K = °C + 273.15. For example, 20 °C equals 293.15 K.
How to convert degrees Celsius to kelvins
K = °C + 273.15
Celsius sets 0° at water's freezing point and 100° at its boiling point at sea level. It is the world's standard scale for weather and cooking outside the US.
The kelvin starts at absolute zero (−273.15 °C), the coldest temperature physically possible. It is the SI base unit used throughout science.
Celsius to Kelvin conversion table
| Celsius (°C) | Kelvin (K) |
|---|---|
| -40 °C | 233.15 K |
| -30 °C | 243.15 K |
| -20 °C | 253.15 K |
| -10 °C | 263.15 K |
| -5 °C | 268.15 K |
| 0 °C | 273.15 K |
| 5 °C | 278.15 K |
| 10 °C | 283.15 K |
| 15 °C | 288.15 K |
| 20 °C | 293.15 K |
| 25 °C | 298.15 K |
| 30 °C | 303.15 K |
| 35 °C | 308.15 K |
| 37 °C | 310.15 K |
| 40 °C | 313.15 K |
| 45 °C | 318.15 K |
Need the opposite direction? Use the Kelvin to Celsius converter, or read our complete guide to temperature conversions for every formula in one place.
Frequently asked questions
What is the formula to convert Celsius to Kelvin?
K = °C + 273.15. For example, 25 °C equals 298.15 K.
What is 100 °C in K?
100 °C equals 373.15 K, using the formula K = °C + 273.15.
Is my data stored when I use this converter?
No. The conversion runs entirely in your browser with JavaScript — nothing you type is sent to a server, logged or stored.