Kelvin to Celsius Converter
To convert Kelvin to Celsius, use the formula C = K - 273.15. For example, 25 Kelvin equals -248.15 Celsius. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
C = K - 273.15
Use the temperature formula to convert Kelvin values to Celsius.
Example Conversions
0 Kelvin (K)
-273.15 Celsius (C)
1 Kelvin (K)
-272.15 Celsius (C)
25 Kelvin (K)
-248.15 Celsius (C)
100 Kelvin (K)
-173.15 Celsius (C)
212 Kelvin (K)
-61.15 Celsius (C)
Conversion Table
| Kelvin (K) | Celsius (C) |
|---|---|
| 0 | -273.15 |
| 1 | -272.15 |
| 10 | -263.15 |
| 20 | -253.15 |
| 25 | -248.15 |
| 32 | -241.15 |
| 37 | -236.15 |
| 50 | -223.15 |
| 75 | -198.15 |
| 100 | -173.15 |
| 212 | -61.15 |
| 273.15 | 0 |
How to Convert Manually
Use these steps to convert Kelvin values to Celsius without the calculator.
- Write down the value in Kelvin (K) that you want to convert.
- Apply the formula: C = K - 273.15.
- For example, converting 10 Kelvin gives -263.15 Celsius.
- Label the result as Celsius (C).
About Kelvin and Celsius
The kelvin is the SI base unit of thermodynamic temperature, defined since 2019 by fixing the Boltzmann constant. Its zero point is absolute zero, and one kelvin equals one degree Celsius in size. The degree Celsius is the SI temperature unit for everyday use, with 0 °C at the freezing point and 100 °C at the boiling point of water at standard pressure. It is offset from the kelvin by exactly 273.15. The two scales are related by the formula C = K - 273.15, not a fixed factor. Kelvin to Celsius conversion comes up most often in physics and chemistry calculations and in color temperature of lighting and displays, typically when figures need restating for weather forecasts outside the US.
Precision and Rounding: Temperature conversions are formula-based, not factor-based, so apply the full formula before rounding. Whole degrees are fine for weather and cooking; lab work, medicine, and HVAC commissioning usually carry one or two decimal places.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 Kelvin equals -258.15 Celsius.
15 K -> -258.15 C
FAQ
How do I convert Kelvin to Celsius?
Use the temperature formula to convert Kelvin values to Celsius.
What is the formula for Kelvin to Celsius?
The formula is C = K - 273.15.
How many Celsius are in 1 Kelvin?
1 Kelvin equals -272.15 Celsius.
Can I convert Celsius back to Kelvin?
Yes. 1 Celsius equals 274.15 Kelvin, and the related converter can reverse the calculation.
What are common names for Kelvin and Celsius?
Kelvin is shown as K and may also be searched as kelvin, °K. Celsius is shown as C and may also be searched as celsius, centigrade, °C.
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