Celsius to Kelvin Converter
Convert degrees Celsius to kelvin with the exact conversion factor, a worked example and a quick-reference table. Runs entirely in your browser.
This converter turns degrees Celsius into kelvin instantly using the standard definition of both units. It includes the formula, a worked example, and a quick table for common amounts, and it works for any value you type — including decimals and negatives where they make sense.
Quick reference — degrees Celsius to kelvin
How to use this calculator
- Enter the value in degrees Celsius in the input box.
- Read the result in kelvin — it updates as you type.
- Use the Swap button to convert in the opposite direction.
- Check the quick-reference table for common degrees Celsius amounts.
The formula
K = °C + 273.15
Worked example
25 °C = 298.15 K — in full, 25 degrees Celsius converts to 298.15 kelvin. Weather forecasts, oven settings and science work are the everyday jobs for this conversion.
Frequently Asked Questions
How do I convert degrees Celsius to kelvin?
Use the formula K = °C + 273.15. For example, 25 °C becomes 298.15 K. The converter above applies the same formula instantly for any value you type.
What are the reference points in Celsius and Kelvin?
At standard pressure, water freezes at 0 °C and boils at 100 °C. In kelvin those same points are 273.15 K and 373.15 K. Normal body temperature, 37 °C, reads 310.15 K.
What is 25 degrees Celsius in kelvin?
25 degrees Celsius is 298.15 kelvin, using the formula K = °C + 273.15. The converter above applies it instantly for any value, including negative temperatures.
Why does converting degrees Celsius to kelvin need addition or subtraction?
Temperature scales do not share the same zero point, so a simple ratio is not enough — each formula combines the 9/5 (or 5/9) degree-size ratio with an offset. Kelvin is the exception that proves the rule: it starts at absolute zero (−273.15 °C), so Celsius-to-Kelvin only shifts by 273.15.