Celsius to Kelvin converter (°C to K)
Convert Celsius (°C) to Kelvin (K) with this free calculator. Type a value, press Convert, and the page applies the same factor shown in the formula below — no rounded shortcut, and nothing is stored on a server.
Kelvin to Celsius calculation ►
How to convert Celsius to Kelvin
The Celsius to Kelvin conversion formula is T(K) = T(°C) + 273.15. Kelvin is the SI unit of temperature; 0 K is absolute zero, the lowest possible temperature.
T(K) = T(°C) + 273.15
Simply add 273.15 to the Celsius temperature. The two scales have the same size degree - they differ only in their zero points:
Example: Convert 25°C to Kelvin:
T(K) = 25 + 273.15 = 298.15 K
What is a Celsius?
Celsius (°C) is the metric temperature scale. Water freezes at 0 °C and boils at 100 °C at standard pressure.
What is a Kelvin?
The kelvin (K) is the SI unit of thermodynamic temperature. Zero kelvin is absolute zero; a kelvin interval equals a Celsius degree.
This page converts temperature from Celsius into Kelvin. Use the formula above for the exact relationship between the two units.
How this calculator works
The form on this page is a Celsius-to-Kelvin converter. After you enter a number, JavaScript multiplies or rearranges it with the published conversion factor and writes the K result in the output box. The step-by-step panel repeats the arithmetic so you can copy it into homework or a spreadsheet.
Reviewed by Hamsen, founder of GigaTables and a biology engineer. See the about page for how formulas are checked before a tool is published.
FAQ
How many K are in 1 °C?
Use the formula in the section above. Temperature and logarithmic units are not a single multiply-by-a-constant step.
How do I convert Celsius to Kelvin?
Simply add 273.15 to the Celsius temperature. The two scales have the same size degree - they differ only in their zero points:
Is this °C to K converter free?
Yes. GigaTables calculators are free to use in a browser. You do not need an account, and the values you type are not uploaded.