Convert from Kelvin to degree Reaumur

Unit Definition (Kelvin)
The Kelvin is the SI base unit of temperature. It was previously called the degree Kelvin (°K). The unit size of Kelvin and degrees Celsius are the same, however the two are offset by ~273°. The temperature in Kelvins is always equal to 273.15 plus the temperature in degrees Celsius. The Kelvin equals exactly 1.8 degrees Fahrenheit.

Unit Definition (degree Reaumur)
The degree Réaumur is a unit of temperature formerly used in continental Europe. The Réaumur temperature scale is named for the French scientist René-Antoine Ferchault de Réaumur (1683-1757). It is similar to the Celsius scale in having its zero point at the freezing temperature of water, but the interval between the freezing and boiling temperatures of water equals 80 °r instead of 100 °C. Therefore, 1 °r equals 1.25 °C or 2.25 °F.