Celsius to Fahrenheit calculation

Celsius to Fahrenheit calculation

There are two scales used in the calculation of Celsius to Fahrenheit. The Fahrenheit scale, °F (used in the US) and the Celsius scale °C which is part of the Metric system that is used in most other countries. Although both of them measure temperature, they use different numbers when showing the temperature reading.

For example, boiling water at normal pressure measures 100° Celsius but in Fahrenheit, this will be indicated as 212 °F. As water freezes, it will give a temperature reading of 0° Celsius but in Fahrenheit, it will be shown as 32° Fahrenheit.  This means that the scales start at different numbers so we can add or subtract by 32 to get the reading of the other. The scales also rise at a different rate and can be multiplied to determine the other reading.

To determine the calculation of these two scales;

180/100 can be simplified as 9/5 and 100/180 can be simplified as 5/9

The easiest way to convert °C to °F will be; multiply the temperature reading in degrees Celsius by 9/5 and then add 32.

T (°F) = T (°C) x 9/5 + 32 is the method used in the calculation.  It can also be simplified further and written as;

T (°F) = T (°C) x 1.8 + 32

Example

Convert 20 degrees Celsius to degrees Fahrenheit

Formula

T (°F) = T (°C) x 1.8 + 32

Solution

T (°F) = 20°C x 1.8 + 32 = 68 °F

Other Methods that work

First, multiply the temperature reading in degrees Celsius by 2. Less 10% of the result and then add to 32 to get the temperature reading in Fahrenheit.

Example

Convert 20 degrees Celsius to degrees Fahrenheit

Solution

20 x 2 = 40

Less 10% of 40 (4) = 40 – 4 = 36

36 + 32 = 68°F