🌡️ Temperature Converter

Celsius to Kelvin
( °C → K )

Instantly convert Celsius to Kelvin. Enter any value below and get an accurate result with the full formula and reference table.

Converter Tool
°C
K
Result
0°C = 273.15 K
273.15
K
The Formula
K = °C + 273.15
Add 273.15 to the Celsius temperature.

How to Convert Celsius to Kelvin

To convert Celsius to Kelvin, simply add 273.15 to the Celsius temperature. This is because the Kelvin scale starts at absolute zero, which is -273.15°C.

Step-by-Step Example

Let’s convert 25°C to Kelvin:

1. Add 273.15: 25 + 273.15 = 298.15
2. So 25°C equals 298.15 K.

Another common example: 100°C (boiling point of water) → 100 + 273.15 = 373.15 K.

Note on Absolute Zero

The Kelvin scale is an absolute temperature scale, meaning 0 K is the lowest possible temperature (absolute zero). The Celsius and Kelvin scales have the same unit size, so converting is just an offset.

When You’d Use Each Unit

Celsius is used in most countries for everyday temperature measurements. Kelvin is used in science, particularly in physics, chemistry, and engineering, because it directly relates to thermodynamic temperature. Converting between them is essential for scientific work.

Conversion Table

Common Celsius values converted to Kelvin — typical values highlighted.

Celsius (°C) Kelvin (K) Approximate
Frequently Asked Questions
How do I convert Celsius to Kelvin? +
Add 273.15 to the Celsius temperature. For example, 25°C + 273.15 = 298.15 K.
What is 0°C in Kelvin? +
0°C = 273.15 K.
What is 100°C in Kelvin? +
100°C = 373.15 K.
What is absolute zero in Celsius? +
Absolute zero is 0 K = -273.15°C.
Do I need to add 273 or 273.15? +
For most everyday purposes, 273 is sufficient, but for precise scientific work, use 273.15. This converter uses the exact 273.15.
Can I convert Kelvin back to Celsius with this tool? +
Yes! Just type a value into the Kelvin field and the Celsius field updates automatically. Or use the ⇄ swap button to switch directions.
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