How to Calculate Area

The unit used to describe area measurement is square metres (m2).  Some examples of general items measured in square metres are carpet, tiles, glass, paint, brick walls, roof tiles etc.

To calculate an area you measure the length and multiply it by the width.

In the following example the amount of flooring required is calculated using a building plan which measures 15.0m x 12.4m. The example also shows how to add a further 10% more to allow for wastage.

The area is 15.0 x 12.4 = 186m2
186m2 *10% = 18.6m2
186m2 + 18.6m2 = 204.6m2 of flooring required.

In another example if a brick wall to be built is 15m long and 2.2m high, how many bricks are needed? If the number of bricks per square metre is 50 then:

The wall is 15m x 2.2m = 33 m2.  

33 m2 x 50 = 1650 bricks are required.


What about a triangle?


The area of a triangle (such as a roof gable) is calculated by multiplying the vertical height by the length of the base and dividing the result by 2.

Also insert example of an area which uses a couple of rectangles and triangle – see “calculate the area web page”

See A Guide to Calculating Paint Amounts