Kelvins to degrees Celsius
Type a value in kelvins to see it in degrees Celsius straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the kelvins box.
- Read the result in degrees Celsius as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
°C = K × 1 − 273.15
Multiply by 1, then subtract 273.15, because the two scales have different zero points.
Example
To convert 25 K to degrees Celsius: 25 × 1 − 273.15 = -248.15 °C.
Conversion table
| Kelvins (K) | Degrees Celsius (°C) |
|---|---|
| -40 | -313.15 |
| -20 | -293.15 |
| -10 | -283.15 |
| 0 | -273.15 |
| 10 | -263.15 |
| 20 | -253.15 |
| 25 | -248.15 |
| 30 | -243.15 |
| 37 | -236.15 |
| 40 | -233.15 |
| 50 | -223.15 |
| 100 | -173.15 |
About the units
- 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.
- 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.
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 kelvins in degrees Celsius?
0 K = -273.15 °C. The formula is °C = K × 1 − 273.15.
How do I convert kelvins to degrees Celsius?
Use °C = K × 1 − 273.15. For example, 25 K = -248.15 °C.
How many kelvins are in one degree Celsius?
1 °C = 274.15 K.
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.