Conversion of Temperature

Quick Fahrenheit/Celsius Conversion:

Try the Temperature Conversion Tool or the Interactive Thermometer or this method:

°C to °F	Multiply by 9, then divide by 5, then add 32
°F to °C	Deduct 32, then multiply by 5, then divide by 9

Or read on to understand why ...

Explanation

There are two main temperature scales. The Fahrenheit Scale (used in the US), and the Celsius Scale (part of the Metric System, used in most other Countries)

They both measure the same thing (temperature!), just using different numbers.

If you freeze water, it measures 0° in Celsius, but 32° in Fahrenheit
If you boil water, it measures 100° in Celsius, but 212° in Fahrenheit
The difference between freezing and boiling is 100° in Celsius, but 180° in Fahrenheit.

Freezing	... to ...	Boiling

Conversion Method

Looking at the diagram, notice:

The scales start at a different number (32 vs 0), so we will need to add or subtract 32
The scales rise at a different rate (180 vs 100), so we will also need to multiply

And this is how it works out:

To convert from Celsius to Fahrenheit, first multiply by 180/100, then add 32

To convert from Fahrenheit to Celsius, first subtract 32, then multiply by 100/180

Note: 180/100 can be simplified to 9/5, and likewise 100/180=5/9.

So, this is the easiest way:

Celsius to Fahrenheit	(°C × ⁹/₅) + 32 = °F
Fahrenheit to Celsius	(°F - 32) x ⁵/₉ = °C

Example 1

Convert 26° Celsius (A nice warm day!) to Fahrenheit

First: 26° × 9/5 = 234/5 = 46.8
Then: 46.8 + 32 = 78.8° F

Example 2

Convert 98.6° Fahrenheit (Normal Body Temperature!) to Celsius

First: 98.6° - 32 = 66.6
Then: 66.6× 5/9 = 333/9 = 37° C

Typical Temperatures

°C	°F	Description
100	212	Water boils
40	104	Hot Bath
37	98.6	Body temperature
30	86	Beach weather
21	70	Room temperature
10	50	Cool Day
0	32	Freezing point of water
-18	0	Very Cold Day
-40	-40	Extremely Cold Day (and the same number!)
(bold are exact)

Conversion Tool

Just type in a value and click in the other box