How do I convert Celsius to Kelvin?

To convert Celsius (°C) to Kelvin (K), use the formula: K = °C + 273.15. For example, 1 °C equals 274.15 K.

How many K are in one °C?

There are 274.15 kelvin in one celsius (1 °C = 274.15 K).

What is the conversion formula for °C to K?

The exact conversion formula is: K = °C + 273.15. This converter uses this formula to give you an accurate result for any value you enter.

What is absolute zero in Celsius?

Absolute zero is 0 K, which equals −273.15 °C. It is the lowest possible temperature, where molecular motion is at its minimum, and Kelvin is anchored to this point.

Why does Kelvin have no degree symbol?

Kelvin is an SI base unit, so temperatures are written as '300 K', not '300 °K'. Celsius and Fahrenheit use the degree symbol, but Kelvin does not.

Is a one-degree change the same in Celsius and Kelvin?

Yes. A change of 1 °C equals a change of 1 K exactly — the scales share the same degree size and differ only by the 273.15 offset in their starting points.

Celsius to Kelvin Converter

This free temperature converter changes Celsius (°C) into Kelvin (K) and back, instantly and in your browser. Kelvin is the SI base unit of temperature used throughout science and engineering, with its zero point at absolute zero — the coldest temperature physically possible.

How it works

Celsius and Kelvin use degrees of identical size; they differ only in where zero sits. Kelvin’s zero is absolute zero (−273.15 °C), while Celsius’s zero is the freezing point of water. The conversion is therefore a simple offset:

K = °C + 273.15

To reverse it, subtract: °C = K − 273.15. Because the degree size is the same, a temperature change of 1 °C is also a change of 1 K — only the starting reference differs.

Example

Convert 100 °C (boiling water) to Kelvin:

100 + 273.15 = 373.15 K

Celsius (°C)	Kelvin (K)
0 °C	273.15 K
20 °C	293.15 K
37 °C	310.15 K
100 °C	373.15 K

All calculations run entirely in your browser with no data sent to any server.