Kelvin (symbol K) is the base unit for measuring temperatures according to the SI system of units. By definition, zero Kelvin is mapped to the so called "absolute zero" temperature, the lowest theoretically meaningful temperature in the universe. The freezing temperature of water is mapped to 273.15 K. The Kelvin is equivalent to the Celsius degree (symbol °C), but the two scales are different since the Celsius scale maps 0 to the freezing point of water, whereas the Kelvin scale maps 0 to the absolute zero. When measuring temperature ranges however, both units are equal. It is acceptable to employ both units concurrently, although it is customary in many scientific fields to use K for temperature intervals and °C for absolute temperature measurements.
Multiple and fraction units of temperature ranges in Kelvins can be defined through the decimal SI prefixes, as shown in next table.
Fahrenheit is a scale for the measurement of absolute temperatures. The Fahrenheit degree (symbol °F) is one step in the scale. The scale was originally defined through key physical temperatures such as human body temperature (≈96°F), freezing of water (32°F) and the stabilized temperature of a solution with equal parts of ice, water and salt (mapped to 0°F, this was probably the coldest material Daniel Gabriel Fahrenheit could produce in his laboratory). Today, the Fahrenheit scale is defined through two characteristic temperatures: freezing of water at 32°F and boiling of water at 212°F. Absolute zero is -459.67 °F.
How to convert Kelvins to degrees Fahrenheit
- Multiply Kelvins with 9/5 (=1.8)
- Subtract 459.67
- The result is the temperature in °F.
For example, to convert 300 K we follow these steps:
\[300 \times 9/5 = 540\]
\[540-459.67 = 8 0.33 °F\]
How to convert degrees Fahrenheit to Kelvins
- Add 459.67 to °F
- Multiply with 5/9
- The result is the temperature in K.
For example, to convert 65 °F we follow these steps:
\[65 + 459.67 = 524.67\]
\[524.67 \times 5/9 = 291.48 K\].
In the following table some key temperatures are presented, both in [°F] and in [K].
|Water freezing point||273.15||32|
|Water boiling point||373.15||212|
|Human body temperature||309.75||98|
Conversion table from [K] to [°F]
In the following table some typical temperatures in Kelvins are converted to degrees Fahrenheit:
Conversion table from [°F] to [K]
In the following table some typical temperatures in degrees Fahrenheit are converted to Kelvins: