The temperature T in degrees Celsius (°C) is equal to the temperature T in
Kelvin (K) minus 273.15.
Formula: °C =K - 273.15
Degrees Celsius ‘°C’ and kelvins ‘K’ have the same magnitude. Only the starting points are different in these two scales. In the Kelvin scale, 0 K is absolute zero, whereas in the Celsius scale, 0°C is the freezing point of water. So, by definition, it means absolute zero (0 K) is equivalent to −273.15 °C.