For example: 68 °F = (68 + 459.67) / 1.8 = 293.15 K
Fahrenheit is a temperature scale with 32 degrees as the freezing point of water and 212 degrees as the boiling point of water under standard atmospheric pressure (101.325 kPa). The absolute zero temperature is -459.67 °F. The symbol for Fahrenheit is "°F".
Kelvin is the base unit of temperature in metric system. For Kelvin temperature scale, the freezing point of water is 273.15 Kelvin and boiling point is 373.15 Kelvin. The absolute zero is defined to be 0 Kelvin. The symbol for Kelvin is "K".