Temperature conversion
21 °C to K
294.15 K
21 degrees Celsius = 294.15 kelvin. Exact factor: K = °C + 273.15.
Live converter
Edit either field — the other updates instantly. Type decimal values like 38.4.
The formula
K = °C + 273.15
Worked example: 21 + 273.15 = 294.15 K.
Values near 21 °C
| °C | K |
|---|---|
| 18 | 291.15 |
| 19 | 292.15 |
| 20 | 293.15 |
| 21this page | 294.15 |
| 22 | 295.15 |
| 23 | 296.15 |
| 24 | 297.15 |
Frequently asked
How do you convert degrees Celsius to kelvin?
Apply the formula K = °C + 273.15. Enter any value in the live converter above and the result updates as you type.
What is 21 °C in K?
21 °C equals 294.15 K. The reference table below shows the values immediately around 21 °C.
Why does temperature conversion add 32?
The two scales have different zero points and step sizes. Water freezes at 32 °F but 0 °C, so the formula rescales by 5/9 and shifts by the 32-degree offset.