Degrees Celsius to kelvins
Type a value in degrees Celsius to see it in kelvins straight away, or type in the second box to convert back.
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How to use it
- Type the value in the degrees Celsius box.
- Read the result in kelvins as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
K = °C × 1 + 273.15
Multiply by 1, then add 273.15, because the two scales have different zero points.
Example
To convert 25 °C to kelvins: 25 × 1 + 273.15 = 298.15 K.
Conversion table
| Degrees Celsius (°C) | Kelvins (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 |
| 100 | 373.15 |
About the units
- Degree Celsius
- A degree Celsius is the same size as a kelvin, but the scale is shifted so that K = °C + 273.15 exactly. Water freezes at 0 °C and boils at about 100 °C at standard pressure.
- Kelvin
- The SI base unit of thermodynamic temperature, starting at absolute zero (0 K). Since 2019 it is defined by fixing the Boltzmann constant at 1.380649 × 10^-23 J/K.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
What is 0 degrees Celsius in kelvins?
0 °C = 273.15 K. The formula is K = °C × 1 + 273.15.
How do I convert degrees Celsius to kelvins?
Use K = °C × 1 + 273.15. For example, 25 °C = 298.15 K.
How many degrees Celsius are in one kelvin?
1 K = -272.15 °C.
Why is temperature conversion not a simple multiplication?
Celsius and Fahrenheit do not start at absolute zero, so converting needs an offset as well as a factor. For example °F = °C × 9/5 + 32, which is why 0 °C is 32 °F, not 0.
At what temperature are Celsius and Fahrenheit equal?
At minus 40: -40 °C is exactly -40 °F.