THE RANKINE SCALE

The Kelvin scale isn’t the only one that exists for defining absolute temperature, although it is by far the most commonly used. Another scale, called the Rankine scale (°R), also assigns the value zero to the coldest possible temperature. The difference is that the Rankine degree is exactly 5⁄9 as large as the Kelvin degree. Conversely, the Kelvin degree is exactly 9⁄5, or 1.8 times, the size of the Rankine degree.
A temperature of 50 K is the equivalent of 90°R; a temperature of 360°R is the equivalent of 200 K. To convert any reading in °R to its equivalent in K, multiply by 59. Conversely, to convert any reading in K to its equivalent in °R, multiply by 95, or exactly 1.8.
The difference between the Kelvin and the Rankine scales is significant at extreme readings. If you hear someone say that a star’s core has a temperature of 30 million °R, they are talking about the equivalent of approximately 16.7 million K. However, you are not likely to hear anyone use Rankine numbers.