Celsius and Fahrenheit Made Simple

by Dennis Randall

For most parents and kids, panic is the order of the day when asked to convert Celsius to Fahrenheit (or visa-versa). Have no fear. It's really not rocket science.

Here's a simple three step process that is easy to recall and use. Just remember the numbers 40 and 5 and 1.8 - if you can remember your phone number, this shouldn't be a problem ;-)

Step 1:

Start with a temperature. It can be either Celsius or Fahrenheit. Add 40.

Step 2:

If you started with Fahrenheit and you want to convert to Celsius, multiply the number created in the first step by .55555 (a decimal point followed by five 5s).

If you started with Celsius and you want to convert to Fahrenheit, multiply the number created in the first step by 1.8

Step 3:

Subtract 40.

That's it! You're all done. Easy, huh?

Example 1: 32º Fahrenheit = ?º Celsius

Step #1: 32 + 40 = 72
Step #2: 72 x .55555 = 39.9996 (round to nearest whole number)
Step #3: 40 - 40 = 0º

Example 2: 0º Celsius = ?º Fahrenheit

Step #1: 0 + 40 = 40
Step #2: 40 x 1.8 = 72
Step #3: 72 - 40 = 32º F

Now go out and amaze your friends. Enjoy ;-)

More on: Building Science Skills