R°
Rankine degree (difference)
Temperature differenceexact by definition
A Rankine degree of difference is exactly 5/9 of a kelvin, the same size as a Fahrenheit degree. A change of 1 R° and a change of 1 F° are the identical interval; only the position of zero separates the two scales, and a difference has no position.
Watch out: Because the interval sizes match, US thermodynamic properties are frequently tabulated per °R while the temperatures beside them are in °F, and the two never need reconciling. That works for differences only. Substituting a Fahrenheit temperature into an equation that wants absolute temperature is the error Rankine exists to prevent.
| 1 R° | 0.55555556 C° |
Solvers that use temperature difference