Celsius to Kelvin Converter
Convert Celsius (°C) to Kelvin (K) instantly and accurately.
Convert Celsius to Kelvin instantly with this free online tool. Type a temperature in Celsius and see the Kelvin value right away, or type Kelvin to convert back. Everything runs in your browser — no sign-up and no waiting.
How to convert Celsius to Kelvin
To convert Celsius to Kelvin, add 273.15. The Kelvin scale starts at absolute zero, the coldest possible temperature, and uses the same degree size as Celsius. For example, 0 °C = 273.15 K and 100 °C = 373.15 K. This converter does the math for you and updates as you type.
- Enter the temperature in Celsius in the first field.
- Read the result in Kelvin in the second field.
- Type into the Kelvin field to convert in the other direction.
Why use this Celsius to Kelvin converter?
- 100% free with no ads, sign-up, or limits.
- Instant, two-way conversion as you type.
- Uses the exact offset of 273.15.
- Runs entirely in your browser.
Frequently asked questions
What is the formula to convert Celsius to Kelvin?
Kelvin = Celsius + 273.15.
What is 0 °C in Kelvin?
0 °C equals 273.15 K, the freezing point of water.
Why is there no degree symbol on Kelvin?
Kelvin is an absolute scale, so temperatures are written as 'K' rather than '°K' — for example 300 K, not 300 °K.