Temperature converter
Kelvin to Celsius
If you need to know how many Celsius one Kelvin contains, the answer is -272.15. The conversion is linear, so 10 K is -263.15 °C and 100 K is -173.15 °C. Use the converter for any other value.
Formula °C = K − 273.15
Need the other direction? Celsius to Kelvin.
How to convert Kelvin to Celsius
Kelvin starts at absolute zero and uses the same increment as Celsius, so K = °C + 273.15. Celsius places 0 at water's freezing point and 100 at its boiling point at sea level.
To convert Kelvin to Celsius, multiply the value in K by -272.15. For example, 10 K × -272.15 = -263.15 °C. This works because the ratio between the two units is constant for every value in temperature.
Worked examples
| K | °C |
|---|---|
| 1 K | -272.15 °C |
| 2.5 K | -270.65 °C |
| 5 K | -268.15 °C |
| 10 K | -263.15 °C |
| 25 K | -248.15 °C |
| 50 K | -223.15 °C |
| 100 K | -173.15 °C |
Reverse conversion
| °C | K |
|---|---|
| 1 °C | 274.15 K |
| 5 °C | 278.15 K |
| 10 °C | 283.15 K |
| 25 °C | 298.15 K |
| 50 °C | 323.15 K |
| 100 °C | 373.15 K |
When this conversion is useful
This is the calculation you need when you are reading a weather forecast, an oven dial or a scientific dataset from another country. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 K is 726.85 °C.
Is the conversion exact?
The formulas are exact for the defined scales; Kelvin and Celsius differ by the fixed offset 273.15.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
K to °C conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Kelvin (K) | Celsius (°C) |
|---|---|
| 1 K | -272.15 °C |
| 2 K | -271.15 °C |
| 3 K | -270.15 °C |
| 4 K | -269.15 °C |
| 5 K | -268.15 °C |
| 6 K | -267.15 °C |
| 7 K | -266.15 °C |
| 8 K | -265.15 °C |
| 9 K | -264.15 °C |
| 10 K | -263.15 °C |
| 11 K | -262.15 °C |
| 12 K | -261.15 °C |
| 13 K | -260.15 °C |
| 14 K | -259.15 °C |
| 15 K | -258.15 °C |
| 16 K | -257.15 °C |
| 17 K | -256.15 °C |
| 18 K | -255.15 °C |
| 19 K | -254.15 °C |
| 20 K | -253.15 °C |
| 21 K | -252.15 °C |
| 22 K | -251.15 °C |
| 23 K | -250.15 °C |
| 24 K | -249.15 °C |
| 25 K | -248.15 °C |
| 26 K | -247.15 °C |
| 27 K | -246.15 °C |
| 28 K | -245.15 °C |
| 29 K | -244.15 °C |
| 30 K | -243.15 °C |
| 31 K | -242.15 °C |
| 32 K | -241.15 °C |
| 33 K | -240.15 °C |
| 34 K | -239.15 °C |
| 35 K | -238.15 °C |
| 36 K | -237.15 °C |
| 37 K | -236.15 °C |
| 38 K | -235.15 °C |
| 39 K | -234.15 °C |
| 40 K | -233.15 °C |
| 41 K | -232.15 °C |
| 42 K | -231.15 °C |
| 43 K | -230.15 °C |
| 44 K | -229.15 °C |
| 45 K | -228.15 °C |
| 46 K | -227.15 °C |
| 47 K | -226.15 °C |
| 48 K | -225.15 °C |
| 49 K | -224.15 °C |
| 50 K | -223.15 °C |
| 60 K | -213.15 °C |
| 70 K | -203.15 °C |
| 80 K | -193.15 °C |
| 90 K | -183.15 °C |
| 100 K | -173.15 °C |
Frequently asked questions
How many Celsius are in 1 Kelvin?
1 K equals -272.15 °C.
How do I convert Kelvin to Celsius?
Multiply the K value by -272.15. Example: 25 K = -248.15 °C.
What is 2.5 K in °C?
2.5 K = -270.65 °C.
Is the K to °C conversion exact?
The formulas are exact for the defined scales; Kelvin and Celsius differ by the fixed offset 273.15.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.