Fahrenheit to Kelvin conversion: °F to K calculator (2024)

Converting from Fahrenheit to Kelvin

Converting from Fahrenheit to Kelvin can be tricky since both units have offsets and their increments are different. Kelvin is an absolute scale whereas Fahrenheit is a relative scale.

To convert Fahrenheit to Kelvin, you need to follow a three-step process. Firstly you will need to remove the Fahrenheit offset by subtracting 32. Next, divide this answer by 1.8 to obtain the Celsius value. Finally add 273.15, the Kelvin offset, to convert the Celsius value to Kelvin.

For example, suppose we have a Fahrenheit temperature of 68°F. First subtract 32 giving 36. Now divide 36 by 1.8 to obtain the Celsius value of 20°C. Finally, add the Kelvin offset value of 273.15 to get the resulting Kelvin value of 293.15K.

Converting from Fahrenheit to Kelvin can be more difficult than similar conversions- when you use the calculator on this page you can see the calculation steps underneath the result to better understand the process.

Why convert from Fahrenheit to Kelvin?

Fahrenheit is commonly used in the United States for general temperature measurments whereas Kelvin is preferred in some scientific applications. Kelvin is an absolute temperature scale that starts at absolute zero which is where all molecular motion ceases.

Converting Fahrenheit to Kelvin allows the values to become independent of the 32°F reference point of freezing water. This is useful in science such as physics, chemistry and engineering. A Kelvin value is always positive removing the complication of negative values.

About the Fahrenheit scale

Fahrenheit is a relative temperature scale created by the Polish-German physicist Daniel Gabriel Fahrenheit. It is mainly used in the United States and is less common in science compared to the Celsius (or Centigrade) scale.

Fahrenheit is based on the freezing and boiling points of water at standard atmospheric pressure with 32°F at freezing point and 212°F at boiling point.

Whilst Fahrenheit is still commonly used in the United States it is important to note that most of the world relies on Celsius.

About Kelvin

Kelvin is an absolute temperature measurement defined in the International System of Units (SI). It is named after the Scottish physicist William Thomson (Lord Kelvin) who studied the field of thermodynamics. The Kelvin scale is based on absolute zero; the point at which all molecular motion ceases.

Unlike most other temperature scales, Kelvin does not have degrees as it is not a relative scale. The Kelvin scale is often used in physics, chemistry, and cosmology.

One advantage of Kelvin is that it does not have negative values making some calculations easier. This is useful in science calculations involving gases as it relates to the kinetic energy of molecules.

Is there an absolute scale related to Fahrenheit like Kelvin is related to Celsius?

Unlike the Celsius and Kelvin scales, Fahrenheit does not have an absolute zero point. Absolute zero is the lowest possible temperature, at which all molecular motion ceases. In the Celsius scale, absolute zero is defined as 0 degrees Celsius, while in the Kelvin scale, it is defined as 0 Kelvin.

The Fahrenheit scale, however, does not have an absolute zero point. Instead, it is based on the freezing and boiling points of water. On the Fahrenheit scale, the freezing point of water is defined as 32 degrees Fahrenheit, and the boiling point is defined as 212 degrees Fahrenheit. This means that the Fahrenheit scale is not directly related to an absolute scale like Kelvin is related to Celsius. While the Celsius and Kelvin scales are based on the properties of water and have a clear reference point at absolute zero, the Fahrenheit scale is based on arbitrary points related to the behavior of water at atmospheric pressure.

Rankine is a unit of temperature measurement in the absolute temperature scale, commonly used in engineering and thermodynamics. It is closely related to the Fahrenheit scale, which is primarily used in the United States for everyday temperature measurements. The Rankine scale is an absolute temperature scale, meaning it starts at absolute zero, where all molecular motion ceases.

The Rankine scale is based on the Fahrenheit scale, with the same size degree and zero point. However, the zero point on the Rankine scale is set at absolute zero, which is equivalent to -459.67 degrees Fahrenheit. Therefore, to convert a temperature from Fahrenheit to Rankine, one simply needs to add 459.67 to the Fahrenheit temperature. Conversely, to convert a temperature from Rankine to Fahrenheit, one subtracts 459.67 from the Rankine temperature.

What happens at absolute zero (0K)?

At absolute zero, 0 Kelvin (0K) or -273.15 degrees Celsius, the temperature is at the lowest possible point anything can possibly be. At this temperature the kinetic energy of atoms and molecules is zero causing them to come to a complete standstill. All molecular motion ceases and matter becomes still.

Several amazing phenomena occur here. As there is no molecular motion there is no heat energy and this has significant implications for the physical properties of the substance. For example, materials become very brittle and their electrical resistance becomes zero. Gases and liquids freeze into solids.

Scientists have never cooled anything down to absolute zero. However they have been able to see the effects of approaching absolute zero. This has provided insights into the behavior of matter and have led to the understanding of superconductors and Bose-Einstein condensates.