Celsius to Kelvin
Type degrees Celsius (°C), see kelvin (K).
By Akash Yadav Updated 23 September 2026
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The formula
How to convert Celsius to kelvin
To change degrees Celsius into kelvin, add 273.15.
kelvin = degrees Celsius + 273.15
Going the other way: degrees Celsius = kelvin − 273.15
A reading of 1 degree Celsius is 274.15 kelvin, but a step of 1 degree Celsius is 1 kelvin — the two scales start counting from different places, which is why the formula shifts the number and never scales it: the steps are the same size. The shift is an exact definition, not a rounded estimate.
Worked example
You have 25 degrees Celsius. Add 273.15. 25 + 273.15 = 298.15 K.
Common values
Celsius to kelvin conversion table
| Degrees Celsius (°C) | Kelvin (K) |
|---|---|
| -273.15 °C | 0 K |
| -200 °C | 73.15 K |
| -100 °C | 173.15 K |
| -40 °C | 233.15 K |
| 0 °C | 273.15 K |
| 10 °C | 283.15 K |
| 20 °C | 293.15 K |
| 25 °C | 298.15 K |
| 30 °C | 303.15 K |
| 37 °C | 310.15 K |
| 50 °C | 323.15 K |
| 100 °C | 373.15 K |
| 200 °C | 473.15 K |
| 500 °C | 773.15 K |
| 1000 °C | 1273.15 K |
Before you rely on it
Kelvin has no degrees, and no negatives
A kelvin is exactly the same size as a Celsius degree, so the conversion is only a shift: add 273.15. A rise of 10 °C is a rise of exactly 10 K. The two scales differ only in where they put zero.
Zero kelvin is absolute zero, the coldest anything can be, at exactly −273.15 °C. Nothing is colder, so a kelvin reading is never negative. If a conversion here gives a negative kelvin figure, the Celsius value you typed is below absolute zero and does not describe a real temperature.
Write kelvin without a degree sign — 300 K, not 300 °K — and say "300 kelvin", not "300 degrees Kelvin". The degree was dropped from the unit’s name in 1967.
Many textbooks round the shift to 273 for quick work, which puts every answer 0.15 K out. That is harmless for weather and matters in a lab; this page keeps the exact figure.
Common questions
Frequently asked questions
How do you convert Celsius to kelvin?
Add 273.15. There is no multiplying, because a kelvin and a Celsius degree are the same size — the scales only disagree about where zero is.
What is 0 °C in kelvin?
0 °C is 273.15 K — the freezing point of water.
What is 25 °C in kelvin?
25 °C is 298.15 K, the standard reference temperature used in chemistry tables.
What is 37 °C in kelvin?
37 °C, normal body temperature, is 310.15 K.
What is 100 °C in kelvin?
100 °C is 373.15 K.
Is a change of 1 °C the same as a change of 1 K?
Yes. A step of 1 °C is exactly 1 K, so temperature differences are the same number in both units. Only readings need the 273.15 added.
Keep going
Related converters
- Kelvin to Celsius K → °C
- Celsius to Fahrenheit °C → °F
- Fahrenheit to Celsius °F → °C
- All temperature converters
Every factor on this page is listed in our conversion methodology.