Kelvin to Fahrenheit – Formula, Examples | K to °F Conversion

Kelvin and Fahrenheit are two popular units/scales for temperature measurement in science. However, the use of units varies from one country to another. Therefore, you must uncover the science of converting Kelvin to Fahrenheit. 

This blog covers Kelvin to Fahrenheit conversion chart, formula, examples, differences between the units, etc. Keep scrolling down to enhance your knowledge of this conversion topic. 

Kelvin’s Definition

Kelvin is the primary unit of temperature measurement in physical sciences. Nevertheless, Celsius is still the dominant scale of temperature measurement in most countries. The Fahrenheit scale is defined with the help of Kelvin.  

The Kelvin scale is an absolute thermodynamic temperature scale, which means that the unit uses absolute zero as its null point. It is represented by K. The unit was created by shifting the initial point of the Celsius scale down from the water’s melting point to absolute zero. Its increments still closely resemble the historical definition of a degree Celsius. 

As of 2019, the Kelvin scale is defined by setting the numerical value of the Boltzmann Constant K to 1.380649×10−23 J⋅K−1. 0 K is considered an absolute zero, and pure water boils to 373.15 K and freezes very close to 273.15 K at standard atmospheric pressure. 

Kelvin’s Origin/ History

The Kelvin scale was invented in 1848 by British physicist William Lord Kelvin. He formulated the idea of absolute temperature, known as the “Second Law of Thermodynamics,” and produced the dynamical theory of heat. 

Scientists have been using the Kelvin as the preferred measurement scale since 1954, when the CGPM (General Conference on Weights and Measures) made decisions about measurement standards and adopted the Kelvin (K) as the base unit for thermodynamic temperature. 

The CGPM fixed a reference point of 273.15 K as the triple point of water. In thermal equilibrium, water simultaneously exists as a solid, liquid, and gas. 

Current Use of Kelvin

The Kelvin Scale is specifically used for measuring the extremes of hot and cold. It is most preferably used by physicists and other scientists who need to register accurate temperatures. The only measurement unit includes the temperature for “absolute zero,” the total absence of heat energy. 

Besides, it is used to define Celsius and Fahrenheit. 

Fahrenheit Definition

Fahrenheit is a temperature scale in which the boiling point of water is 212 degrees, whereas the freezing point of water is 32 degrees. The temperature in the scale is denoted by °F, or if used for scientific purposes, F alone represents Fahrenheit. Primarily, the scale is used in the United States. 

Since the Fahrenheit scale is now defined by the Kelvin, a temperature interval of 1 degree Fahrenheit is equal to an interval of 5/9 Kelvins. The absolute zero for this scale is −459.67 °F. 

Fahrenheit’s Origin/ History

Daniel Gabriel Fahrenheit proposed his temperature scale in 1724. It was based on two reference points of temperature. The zero point was computed by putting the thermometer in ice, water, ammonium chloride, or sea salt mixture. The combination created a eutectic system that stabilized the temperature automatically at zero degrees. He referred to it as the freezing point of water. A second point was approximately the temperature of the human body at 96 degrees Fahrenheit. The third point was marked as the ice and water temperature at 32 degrees. 

However, Fahrenheit soon realised that water boils at 212 degrees using the F scale. In 1776, a committee of the Royal Society led by Henry Cavendish adopted the freezing and boiling points of water as the fixed points of thermometers became prominent following Andres Celsius’s work. 

The Fahrenheit scale was redefined under this system, and the boiling and freezing points of water were set exactly to 32 °F and 212 °F or 180 degrees higher. Today’s Fahrenheit scale doesn’t represent 

0 °F as the eutectic temperature of ammonium chloride brine. Rather, today, the eutectic temperature is about 4 °F on the final Fahrenheit scale.

Current Use of Fahrenheit

Fahrenheit is used in the United States and its associated states and territories, as well as in Liberia and the Cayman Islands for daily applications. 

For instance, Fahrenheit is used in the U.S for weather forecasts, food cooking, and freezing temperatures. Besides, scientists, including meteorologists, employ degrees Fahrenheit and Celsius. 

Relationship between Kelvin and Celsius

The relationship between Kelvin and Celsius can be described as follows:

1 Kelvin = -457.87 °F

While 1 Fahrenheit = 255.928 Kelvin

How to Convert Kelvin to Fahrenheit?

Either you can use Square Yards’ Kelvin to Fahrenheit converter or Kelvin to Fahrenheit formula for K to F conversion. 

In the converter, you are simply required to fill in the value of Kelvin in the required field and press enter. The value in Fahrenheit will be displayed in the blink of an eye.

Another method requires a bit of addition, subtraction, multiplication, and division skill. Simply multiply the value of Kelvin by 9/5 or 1.8 and subtract the same from 459.67. The result will be your value in Fahrenheit. 

Kelvin to Fahrenheit Conversion Formula

The Kelvin to Fahrenheit formula is described below:

T(°F) = T(K) × 9/5 – 459.67

Solving this equation, you can easily find out the temperature value in Fahrenheit. For a better understanding, let us solve a few examples of the same:

Example 1: Convert 100 Kelvin to Fahrenheit

Sol: Putting the value of Fahrenheit in Kelvin to F formula, we will get-

°F = 100 x 9/5 – 459.67 = -279.67 °F.

Therefore, 100 Kelvin is equal to – 279.67 °F. 

Example 2: Convert 750 Kelvin to Fahrenheit

Sol: Fahrenheit = 750 x 9/5 – 459.67 = 890.33 °F. 

Hence, 750 Kelvin is equal to 890.33 °F. 

Other Formulas for Converting K to °F

There are a few other formulas for Kelvin to Fahrenheit conversion. However, one way on another, all of them are the same. They are as follows:

• °F = (K − 273.15) × 9/5 + 32 
• °F = 1.8 x (K – 273.15) + 32
• T(F) = T(k) x 1.8 – 459.67

Difference between Kelvin and Fahrenheit

Even though both are temperature units, they vary in values and some other terms. The differences between the two have been described in the table below:

Don’t miss It!

Kelvin to Celsius Conversion Chart

Common Conversions from Kelvin to Fahrenheit

Let us pick on some common conversion values and convert them from Kelvin to Fahrenheit.

Example 1: Convert 5 Kelvin to Fahrenheit

Sol: Putting the value of Kelvin in the formula below, we will get-

T(°F) = T(K) × 9/5 – 459.67 = 5 x 1.8 – 459.67 = -450.67 °F.

5 Kelvin = -450.67 F.
Example 2: Convert 250 Kelvin to Fahrenheit

Sol: Fahrenheit = 250 x 1.8 – 459.67 = -9.67 °F

250 Kelvin =-9.67°.

Example 3: Convert 500 Kelvin to Fahrenheit

Sol: Fahrenheit = 500 x 1.8 – 459.67 = 440.33 °F

500 Kelvin = 440.33 °F.

FAQ’s about Kelvin to Fahrenheit Conversion