Converting Celsius to Fahrenheit in your head easily.

Questions and answers on how to convert things from one unit or system to another
Forum rules
Dear convert-me.com forum visitors,

Our forum has been available for many years. In September 2014 we decided to switch it to read-only mode. Month after month we saw less posts with questions and answers from real people and more spam posts. We were spending more and more resources cleaning the spam until there were less them 1 legitimate message per 100 spam posts. Then we decided it's time to stop.

All the posts in the forum will be available and searchable. We understand there are a lot of useful information and we aren't going to remove anything. As for the new questions, you can always ask them on convert-me.com FaceBook page

Thank you for being with us and sorry for any inconveniences this could caused.

Converting Celsius to Fahrenheit in your head easily.

Postby Ken Chevy » Tue Sep 27, 2005 10:49 am

Double the celsius number and subtract 10 % then add 32 and you have how many degrees fahrenheit it is.

I subtract the 10% from the doubled number after adding the 32 to it, I find that is easier to do in my head. Lots easier for me than the multiplying by 9/5 and adding 32.

Try a couple in your head, example:

20C = 20+20=40-4 (the 10%) =36+32= 68F

25C = 25+25=50-5=45+32=77F

33C = 33+33=66-6.6=59.4+32=91.4F

1C = 1+1=2-.2=1.8+32=33.8F

I find it easier to subtract the 10% of the 1st part after I add the 32, so in my head the last example would be 1+1=2+32=34-.2=33.8F

or 41+41+32=114-8.2=105.8F

Anyone else have a way to do it in their head beside the 9/5 way? If so, I would like to give it a try without pencil and paper too.
Ken Chevy
competent
 
Posts: 57
Joined: Mon Sep 26, 2005 11:22 am
Location: Salem, OR, USA

Postby Guest » Tue Sep 27, 2005 6:04 pm

I'm not sure it is easier. Some people like the formula
F + 40 = 1.8*(C + 40), which is based on -40 F = -40 C.

Add 40 to the Celsius temperature
Use doubling, less 10% for the 1.8 factor
Subtract 40
Guest
 

Postby Guest » Wed Sep 28, 2005 1:25 pm

23
63 +40
126 double
113.4 -12.6
73.4 -40

Yes, that works too fairly easily in my head. Thanks.
Guest
 


More info

  • List of all units you can convert online
  • Metric conversion
  • Convert pounds to gallons
  • Convert grams to cups
  • Grams to milliliters
  • Imperial vs US Customary
  • History of measurement
  • Return to How to convert?



    Our Privacy Policy       Cooking Measures Converter       Metric conversions

    cron