About the k to °c calculation
Converting kelvin to celsius is not a simple multiplication, because the two scales start from different zero points. One kelvin corresponds to -272.15 celsius, but that ratio does not hold at other values — the formula below is what you actually need. The SI temperature unit. It starts at absolute zero, so it never goes negative and takes no degree symbol. The everyday temperature scale nearly everywhere, with 0 at the freezing point of water and 100 at its boiling point.
Formula
°C = K − 273.15Worked example
Converting 300 K through the formula above gives 26.85 °C.
Frequently asked questions
How many celsius are in a kelvin?
One kelvin equals -272.15 celsius. Because these are temperature scales with different zero points, this is not a ratio you can multiply by — you have to apply the full formula for any other value.
How do I convert celsius back to kelvin?
Reverse the formula: undo the addition first, then the multiplication. One degree Celsius works out as 274.15 kelvin. Our Celsius to Kelvin page does it for you.
Is this conversion exact?
Yes. The Celsius, Fahrenheit and Kelvin scales are defined in terms of each other exactly, so the conversion carries no rounding error beyond what we display.
Where is each of these units used?
Kelvin: the SI temperature unit. It starts at absolute zero, so it never goes negative and takes no degree symbol. Celsius: the everyday temperature scale nearly everywhere, with 0 at the freezing point of water and 100 at its boiling point.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units