The Kelvin, the SI unit of thermodynamic temperature is defined as
1/100 of the temperature difference between the ice-point and the steam - point
1/100 the of the temperature difference between the triple point of water and the steam - point
The fraction 1/273.16 of the thermodynamic temperature of the triple-point of water
The fraction 1/373.15 of the thermodynamic temperature of the steam - point.