How to convert °C to K
K = °C × 1 + 273.15. The offset accounts for the different zero points of these temperature scales.
Worked example
For a temperature reading of 20 °C converts to 293.15 K.
- Start with 20 °C.
- Apply K = °C × 1 + 273.15.
- Report 293.15 K, rounded to the precision of your original measurement.
Check the reverse conversion
1 K = -272.15 °C. Use the kelvin to celsius converter to calculate in the opposite direction. This has its own formula and reference table.
Definitions that matter
These formulas convert temperature readings. For a temperature change, use the scale factor without adding a zero-point offset. Readings below absolute zero are rejected.
The source scale maps to kelvin as K = °C × 1 + 273.15. The destination conversion reverses its scale and zero-point offset.
Sources and precision
Definitions: BIPM SI Brochure. Calculations use double precision; the tool defaults to a readable rounded result, while tables show up to ten significant digits. Displaying more digits does not increase the accuracy of the original measurement.
Read our calculation methodology and content standards, or continue with temperature readings versus temperature differences.