The Rankine to Kelvin conversion is essential in thermodynamics and engineering, as both are absolute temperature scales starting at absolute zero. To convert a temperature from Rankine (°R) to Kelvin (K), multiply the temperature in Rankine by 5/9: T(K) = T(°R) × 5/9. For example, converting 300°R to Kelvin: T(K) = 300°R × 5/9 = 166.67 K. This conversion is crucial for scientific calculations, especially when interpreting data across different temperature scales.