Temperature Calculator 101: The Most Common Conversion Formulas You Should Know

Sharing is caring!


Temperature Calculator 101: The Most Common Conversion Formulas You Should Know Your body temperature can vary throughout the day, and depending on your location and the season, you may need to convert between Celsius, Fahrenheit, and Kelvin to ensure you’re dressed appropriately. 

Read through this guide to learn more about these common conversion formulas and how to use them in your everyday life.

Celsius to Kelvin

As you learned from school about a temperature calculator, the Celsius scale is a temperature measurement based on the original scale set by Anders Celsius in 1742. 

Kelvin is the SI base unit of thermodynamic temperature, meaning it goes from absolute zero to a point. At this point, all molecular motion ceases, and everything becomes 100% energetically random. 

Technically, this is known as zero K (Kelvin). To convert Celsius to Kelvin, subtract 273 degrees (Celsius) from 100 degrees, giving you the Kelvin number. 

Likewise, converting Fahrenheit to Kelvin can add 460 degrees (Fahrenheit) to 280 degrees on the same scale.

Kelvin to Celcius

To convert from degrees Kelvin to Celcius, use the following formula: K = C + 273.15. It’s also important to know that Celsius ranges from -273.15°C to 100°C, while kelvin contents are 0K (absolute zero) and 13.8K (degrees Celsius). 

As such, it is impossible to convert from Celsius to kelvin using this formula.

Fahrenheit to Celcius

It’s often said that winter is coming. We all know what this means, don’t we? There’s a lot of snow around these days. To figure out just how much snow we’re dealing with and what it means in terms of temperature, we’ll need to convert from Fahrenheit (°F) to Celsius (°C). 

Here are the formulas you should know! Convert °F to °C by subtracting 32 and multiplying by 5/9 or dividing by 9/5*, then add 32. 

For example, if the Fahrenheit reading is 20 degrees: 20-32= -12 + 12*5/9 = -1 * 9/5 + 32 = 3 degrees Celsius. 

To calculate °C to °F, use either equation above but replace ° with degrees.

For example, if the Celsius reading is 4 degrees: 4-32= -28 + 28*5/9 = -7 * 9/5 + 32 = 21 degrees Fahrenheit.

Celsius to Fahrenheit

The formula for converting Celsius to Fahrenheit is as follows: C * 9/5 + 32 = F (where C=degrees Celsius and F=degrees Fahrenheit). If the answer is above 100 degrees, it will be adjusted accordingly. 

So if you want to convert 45 degrees Celsius to Fahrenheit, 45 * 9/5 + 32 = 78.9 degrees Fahrenheit.

Fahrenheit to Kelvin

The conversion equation for converting Fahrenheit to Kelvin is as follows: Kelvin=Fahrenheit+273.15. For example, if the temperature in Fahrenheit is 86 degrees, its equivalent in Kelvin would be 299.6 degrees. 

Conversely, if the temperature in Fahrenheit is 277 degrees, its equivalent in Kelvin would be 313.3 degrees. 

Kelvin to Fahrenheit

The conversion of Kelvin to Fahrenheit is a little bit more complicated but not too difficult. All you need is the following formula: K = T(F-32)/1.8 + 32, where K is the temperature in degrees Kelvin and T is the temperature in degrees Fahrenheit. 

For example, let’s say you want to know what 54°K equals in Fahrenheit. Plug 54 into K and use 1.8 for 1°C (the F conversion factor). Then plug 54 – 32 into the first parentheses and 496 into the second parentheses (since there are 496 degrees between 0°C and 100°C). After adding all these numbers together, we get 308°F! 

Isn’t that great? Now we can convert any temperature from Celsius or Kelvin directly to Fahrenheit with this handy little equation!


So there you have it! A concise guide to conversion and common formulas for measuring temperature. 

Hopefully, this will be helpful to your endeavors in the future, and as always, feel free to ask me any questions.