Celsius to Kelvin Converter
Convert degrees Celsius (°C) to kelvins (K). The two scales start at different zero points, so the conversion uses a formula rather than a single factor: K = °C + 273.15.
Formula: multiply the source value by 274.15
Quick Conversions
About this tool
On the Celsius scale, water freezes at 0 °C and boils at about 100 °C at sea-level pressure. The kelvin is the SI unit of temperature. 0 K is absolute zero, and a change of 1 K equals a change of 1 °C.
How to use it
- Type a value in degrees Celsius in the first field. The unit menus start on °C → K.
- Read the result in kelvins. It updates as you type; use Precision to choose how many decimals are shown.
- Press the swap button, or open the Kelvin to Celsius converter, to convert kelvins back to degrees Celsius.
K = °C + 273.15
°C = K − 273.15
Examples
-273.15 °C to K (absolute zero)
Using K = °C + 273.15: -273.15 °C = 0 K.
0 °C to K
Using K = °C + 273.15: 0 °C = 273.15 K.
25 °C to K (a warm room)
Using K = °C + 273.15: 25 °C = 298.15 K.
Degrees Celsius to kelvins conversion table
| Degrees Celsius (°C) | Kelvins (K) |
|---|---|
| -40 | 233.15 |
| -20 | 253.15 |
| -10 | 263.15 |
| 0 | 273.15 |
| 10 | 283.15 |
| 15 | 288.15 |
| 20 | 293.15 |
| 25 | 298.15 |
| 30 | 303.15 |
| 37 | 310.15 |
| 40 | 313.15 |
| 50 | 323.15 |
| 100 | 373.15 |
Kelvins to degrees Celsius (reverse)
| Kelvins (K) | Degrees Celsius (°C) |
|---|---|
| 0 | -273.15 |
| 200 | -73.15 |
| 250 | -23.15 |
| 273.15 | 0 |
| 283.15 | 10 |
| 293.15 | 20 |
| 298.15 | 25 |
| 300 | 26.85 |
FAQ
What is the formula to convert °C to K?
K = °C + 273.15. For example, 10 °C is 283.15 K.
How do I convert K back to °C?
Use the reverse formula, °C = K − 273.15.
Why add 273.15 and not 273?
The scales are defined so that 0 °C is exactly 273.15 K. Rounding to 273 introduces an error of 0.15 K, which matters in lab work.
Is the conversion exact?
Yes. The scale definitions (0 °C = 273.15 K, and one Fahrenheit degree is 5/9 of a kelvin) are exact. Results are only rounded for display.