This degrees Celsius to kelvin converter turns any °C reading into K instantly, in your browser, with the formula shown so you can check the result by hand. Degrees Celsius are part of the metric system used in most countries; kelvin are an SI unit used in science and engineering. Water freezes at 0 °C (273.15 K) and boils at 100 °C (373.15 K) at sea level.
The formula is K = °C + 273.15. For a quick mental estimate between Celsius and Fahrenheit, double the Celsius value and add 30; it is within a few degrees for everyday temperatures. Normal body temperature is 37 °C, which is 310.15 K.
°C to K formula
K = °C + 273.15
Degrees Celsius to Kelvin conversion table
| degrees Celsius | kelvin | Rounded |
|---|---|---|
| -40 °C | 233.15 K | 233 |
| -30 °C | 243.15 K | 243 |
| -20 °C | 253.15 K | 253 |
| -10 °C | 263.15 K | 263 |
| 0 °C | 273.15 K | 273 |
| 10 °C | 283.15 K | 283 |
| 20 °C | 293.15 K | 293 |
| 25 °C | 298.15 K | 298 |
| 30 °C | 303.15 K | 303 |
| 37 °C | 310.15 K | 31 |
| 40 °C | 313.15 K | 313 |
| 50 °C | 323.15 K | 323 |
| 60 °C | 333.15 K | 333 |
| 70 °C | 343.15 K | 343 |
| 80 °C | 353.15 K | 353 |
| 90 °C | 363.15 K | 363 |
| 100 °C | 373.15 K | 373 |
| 150 °C | 423.15 K | 423 |
| 200 °C | 473.15 K | 473 |
| 250 °C | 523.15 K | 523 |
| 300 °C | 573.15 K | 573 |
| 350 °C | 623.15 K | 623 |
| 400 °C | 673.15 K | 673 |
| 450 °C | 723.15 K | 723 |
Frequently asked questions
How many kelvin are in 20 degrees Celsius?
20 °C = 293.15 K. Apply the formula K = °C + 273.15. The converter on this page does the same arithmetic for any value, including decimals.
What is the formula to convert degrees Celsius to kelvin?
K = °C + 273.15. Temperature scales have different zero points, so you cannot simply multiply; the offset matters. Worked example: 100 °C = 373.15 K.
Is -10 °C the same as 263.15 K?
Yes. -10 °C = 263.15 K, a common winter temperature. Notice that -40 is the one point where Celsius and Fahrenheit agree: -40 °C equals -40 °F.
How do I convert kelvin back to degrees Celsius?
Reverse the formula: °C = K − 273.15. Or use the kelvin to degrees Celsius page linked above, which has its own table and examples.