Celsius to Kelvin Converter

Convert degrees Celsius (°C) to kelvins (K) instantly. Type a value — the result updates as you type, and the swap button converts the other way.

Celsius to Kelvin formula

K = °C + 273.15

To convert degrees Celsius to kelvins, apply the formula K = °C + 273.15. For example, 25 °C:

K = 25 + 273.15
K = 298.15

So 25 °C = 298.15 K.

Mental math shortcut

This conversion is exact, so there is no need to estimate: just add or subtract 273.15.

Celsius to Kelvin conversion table

Celsius	Kelvin
-273.15 °C	0 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
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

Kelvin back to Celsius

The same values converted the other way, rounded for everyday use:

Kelvin	Celsius
0 K	-273.15 °C
173.15 K	-100 °C
233.15 K	-40 °C
273.15 K	0 °C
283.15 K	10 °C
293.15 K	20 °C
298.15 K	25 °C
310.15 K	37 °C

About the units

Celsius (°C)

The Celsius scale sets the freezing point of water at 0 °C and its boiling point at 100 °C (at sea level). It is used for everyday temperatures in almost every country.

Kelvin (K)

The kelvin is the SI unit of temperature. It starts at absolute zero (0 K = −273.15 °C) and uses degrees the same size as Celsius, so it never goes negative.

Frequently asked questions

How do you convert Celsius to Kelvin?

Use K = °C + 273.15. For example, 25 °C = 298.15 K.

What is 25 Celsius in Kelvin?

25 °C = 298.15 K.

How do I convert Kelvin back to Celsius?

Use the reverse formula: °C = K − 273.15.