When it comes to converting temperatures, there are two ways. The easiest is to use a converter such as this one. If you don’t convert temperatures often, this may be a fine choice. But, if you don’t want to depend on converters to switch between scales or you need the ability to convert manually, all you will need to do is learn some rather simple equations where you simply replace the value of the temperature you know (F for Fahrenheit, C for Celsius, and K for Kelvin) and solve for the one you don’t.

Between Fahrenheit and Celsius

To make a conversion between either set of units, use the following equations:

For Celsius:

C = (5/9)(F-32)

And for Fahrenheit:

F = (9/5)C + 32

For example, I know that the temperature outside is 6°C. To find the temperature in Fahrenheit, I simply replace C with 6 and solve for F as shown below:

F = (9/5)6 + 32

F = 10.8 + 32

F = 42.8

As you can see, the temperature is 42.8°F. Now using the other equation, we can do the same process in reverse:

C = (5/9)(42.8-32)

C = (5/9)(10.8)

C = 6

Between Celsius and Kelvin

This one is even easier. Either know that any reading in Kelvin will always be 273° higher in Celsius. If you must have an equation, here it is:

K = C + 273

So 0°C is 273K, 27°C is 300K, and so on and so forth. Remember that Kelvin does not use degrees!

Between Fahrenheit and Kelvin

This conversion simply combines the first two equations.

For Fahrenheit:

F = (9/5)K − 459.67

For Kelvin:

K = (F+459.67)(5/9)

Let’s say it’s 67.1°F outside. I would solve for the Kelvin temperature like so:

K = (67.1+459.67)(9/5)

K = (526.77)(9/5)

K = 948.2

Thus, the temperature is 948.2K. Now let’s say you know the Kelvin reading but need to find Fahrenheit:

F = (5/9)(948.2) – 459.67

F = 526.8– 459.67

F = 67.1

Of course, it is fine to only remember the first two sets of equations. All this would mean is that you would have to convert Fahrenheit to Celsius before you could convert them to Kelvins and vice versa. Just use the method that works the best for you.