A kelvin (K), is the base unit of temperature in the International System of Units (SI).

1 kelvin = -272.15 Celsius

1 kelvin = -457.87 Fahrenheit

Unlike the Fahrenheit and Celsius scales, the Kelvin scale does not have degrees. Each increment is just 1 kelvin. The Kelvin scale is referred to as an absolute temperature scale, and 0 kelvin is set at absolute zero, the temperature at which almost all molecular motion stops. Other notable temperatures on the kelvin scale are 273.15 K, the temperature at which water freezes, and 373.15 K, the temperature at which water boils.

Each unit in the Kelvin scale is the same size as a degree in the Celsius scale. Since 0 K is at absolute zero, there are no negative values in the Kelvin scale. This property of the Kelvin scale is one reason that it is widely used in scientific contexts. It is easier to compare temperature values when there are no negative numbers on the scale.

Converting kelvins to Celsius and Fahrenheit

Since kelvins and degrees Celsius share the same unit size, it is relatively easy to convert between a value in kelvins and a value in °C. To convert from a kelvin to a °C, just subtract 273.15. To convert from °C to kelvins, add 273.15.


Convert 25°C to kelvins:

25°C + 273.15 = 298.15 K

Converting between kelvins and Fahrenheit involves converting either unit to °C first. To convert from kelvins to °F, we first convert to °C by subtracting 273.15. Then we multiply by and add 32. To convert from °F to kelvins, subtract 32 then divide by to convert to °C. After that, add 273.15.


1. Convert 295.3722 K to °F:

(295.3722 K - 273.15) × + 32 = 72°F

2. Convert 212°F to kelvins:

(212°F - 32) ÷ + 273.15 = 373.15 K