The Rankine scale is a temperature scale named after the Scottish physicist and engineer, Willam John Macquorn Rankine (1820 − 1872), who proposed it in 1839. The symbol for a degree Rankine is °R and it is based on one degree Rankine being equal to one degree Fahrenheit. As with the Kelvin scale, zero in the Rankine scale is absolute zero. A temperature of −459.67 °F is exactly 0 °R.
The melting point of water in the Rankine scale is 491.67 °R and the normal boiling point of water is 671.67 °R (i.e., 459.67 + 212).
The different temperature scales (kelvin, Celsius, Fahrenheit and Rankine) can be converted into each other. (See the Temperature conversion article.)