Converting temperature - fahrenheit to celsius


You're about to learn how to convert fahrenheit to celsius (also known as centigrade).


Fahrenheit and celsius are scales of temperature with units °F (degrees fahrenheit) and °C (degrees celsius).


So what's the fahrenheit -> celsius formula?


If you know the temperature in °F, you can change it to °C using the formula



We'll use examples which are the reverse of those considered in celsius to fahrenheit - hopefully this will help you appreciate how easy it is to convert from one measure of temperature to another and back again!


The freezing point of water is 32 degrees fahrenheit - what is it in degrees celsius?


Here's the calculation


°C

=  (°F  -  32)  x  5/9

=  (32  -  32)  x  5/9

=  0  x  5/9

=  0


i.e. the freezing point of water in degrees celsius is zero.


Next what's the boiling point of water in °C if it's 212°F?

°C

=  (°F  -  32)  x  5/9

=  (212  -  32)  x  5/9

=  180  x  5/9

=  100


i.e. the boiling point of water's 100°C.


A human's normal body temperature is 98.6°F - work out the equivalent temperature in °C


°C

=  (°F  -  32)  x  5/9

=  (98.6  -  32)  x  5/9

=  66.6  x  5/9

=  37


i.e. the equivalent temperature is 37°C.


Calculate 14, 69.8 and 140 degrees fahrenheit in degrees celsius


Working through each of these calculations in turn gives

°C  =  (°F  -  32)  x  5/9  =  (14  -  32)  x  5/9  =  -18  x  5/9  =  -10

°C  =  (°F  -  32)  x  5/9  =  (69.8  -  32)  x  5/9  =  37.8  x  5/9  =  21

°C  =  (°F  -  32)  x  5/9  =  (140  -  32)  x  5/9  =  108  x  5/9  = 60


How about a fahrenheit to celsius chart?


Notice this is the same as the celsius to fahrenheit conversion chart only flipped!


You probably don't need two charts - just read left to right, or right to left, depending on which temperature scale you're converting from/to.


Now have a go at your own °F to °C conversions


Changing fahrenheit into celsius becomes easier with a little practice. Why not add the results of your calculations to the °F to °C chart?


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