Celsius to Kelvin calculatorway Celsius to Kelvin conversion Converting from Celsius to Kelvin is a common task for engineers and scientists. The conversion between the two temperature scales is not complicated, but a little tricky. The key to a correct Celsius to Kelvin conversion is to remember that the "Kelvin" scale is actually a relative scale. In other words, a temperature of 100 Kelvin is equal to a temperature of 273.15 degrees Celsius. conversion of Celsius temperature scale to Kelvin temperature scale, simply add 273.15.