# Fahrenheit

## Comment by George Jones on May 31st, 2017 at 8:57 pm

There are formulae that are easier to use to mentally convert Fahrenheit and Celsius degrees. They are:
F = (C+40)*9/5-40 and C=(F+40)*5/9-40
I suggest that you add these to the appropriate articles.

George Jones

## Comment by Jennifer Tanabe on June 1st, 2017 at 1:38 pm

Thank you, George, for your feedback. Those formulae will be added as you suggested.

## Comment by George Jones on June 12th, 2017 at 7:45 pm

I found as below. Thanks for that. I suggest:

http://www.csgnetwork.com/tempconv.html
To remember whether to use 5/9 or 9/5 when converting from Fahrenheit to Celsius or Celsius to Fahrenheit, just simply remember, F (for Fahrenheit) begins with the same letter as Fraction. 5/9 is always a Fraction; while 9/5 is also a fraction, in this form, it is Clearly a whole number plus a fraction (1 and 4/5). Thus, if you want to convert Fahrenheit (F) to Celsius (C), then use the Fraction 5/9; Celsius (C) to Fahrenheit (F), use the other, 9/5, which is Clearly not just a fraction.

In summary, add 40, (F to C) multiply by Fraction…(C to F) multiply by the other, subtract 40. Go figure…

->
To remember whether to use 5/9 or 9/5 when converting from Fahrenheit to Celsius or Celsius to Fahrenheit, just remember that at the boiling point of water Fahrenheit is a bigger number than Celcius (212 is bigger than 100) so you need to use the bigger fraction 9/5 to get a bigger number when converting to Fahrenheit. Similarly, when converting to Celcius use the smaller fraction 5/9 to get the smaller number result (100 is smaller than 212).

In summary, add 40, (F to C) multiply by 5/9 to get a smaller number …(C to F) multiply by 9/5 to get a bigger number, subtract 40. Go figure…

## Comment by Jennifer Tanabe on June 13th, 2017 at 4:05 pm

Thank you, George, for taking the time to help make New World Encyclopedia a valuable information resource. The article will be updated soon.

## Comment by George Jones on June 16th, 2017 at 2:15 am

Sorry, my spelling of Celsius in incorrect.

Am only too happy to help.

George