The formula
To convert °C to K, use: K = °C + 273.15
Celsius to Kelvin
Convert °C to K instantly — with the formula, a table, key reference temperatures, and a live calculator.
0 °C equals 273.15 K.
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Result (K)
°C to K table
| °C | K |
|---|---|
| -40 °C | 233.15 K |
| -20 °C | 253.15 K |
| -10 °C | 263.15 K |
| 0 °C | 273.15 K |
| 5 °C | 278.15 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 |
| 40 °C | 313.15 K |
| 50 °C | 323.15 K |
| 100 °C | 373.15 K |
K to °C (reverse)
| K | °C |
|---|---|
| 0 K | -273.15 °C |
| 100 K | -173.15 °C |
| 200 K | -73.15 °C |
| 250 K | -23.15 °C |
| 273.15 K | 0 °C |
| 293.15 K | 20 °C |
| 300 K | 26.85 °C |
| 310.15 K | 37 °C |
| 373.15 K | 100 °C |
Key temperatures
| Reference point | °C | K |
|---|---|---|
| Absolute zero | -273.15 °C | 0 K |
| Freezing point of water | 0 °C | 273.15 K |
| Comfortable room | 21 °C | 294.15 K |
| Body temperature | 37 °C | 310.15 K |
| Hot summer day | 40 °C | 313.15 K |
| Boiling point of water | 100 °C | 373.15 K |
How it scales
Freezing, body & boiling point
°C (°C)K (K)
Reference points in K
Why temperature conversions need an offset
Unlike length or speed, temperature scales have different zero points. Celsius starts at water's freezing point (0 °C), Kelvin at absolute zero (0 K = −273.15 °C), and Fahrenheit at a historical reference (0 °F ≈ −17.8 °C). That is why a single multiplier is not enough — you also need an offset.
Absolute zero is 0 K = −273.15 °C = −459.67 °F — nothing can be colder. For more pairs, use our temperature conversion hub.
Related conversions
Frequently asked questions
How do I convert °C to K?
Use the formula K = °C + 273.15. For example, 25 °C equals 298.15 K.
What is the formula for °C to K?
The exact conversion formula is: K = °C + 273.15.
What is 0 °C in K?
0 °C equals 273.15 K.
What is absolute zero?
Absolute zero is the lowest possible temperature: 0 K = −273.15 °C = −459.67 °F. Nothing can be colder.
Why can't I convert temperatures with a single factor?
Temperature scales have different zero points. Celsius starts at water's freezing point, Kelvin at absolute zero, and Fahrenheit at a historical reference. That is why conversions need an offset, not just a multiplier.
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