Calculating Area, for use when ordering materials



Calculating Area



At times during construction or renovations you will need to do a calculation on area, or also known as square metres (m2).

It would be good to know this when ordering items such as Paint, Floor coverings (floating, timber, carpet, lino), Turf, exterior/interior cladding and so on, the same calculations are used to find the square metres of your home or property. Trust me it is handy at times.


To calculate area for paint:

When renovating your home, weather it is just a room or the whole home, it is a great idea to know what you are getting yourself in for, money wise. Find out how many square metres of wall you have by measuring length x height of each wall, minus doors and windows.

If you are painting the whole house, measure the length of all walls x by height to get your homes total square metres then minus doors and windows m2.

Measure the rooms floor area, length x width to get the total ceiling area.


To find out how many litres you require, first determine the paint to be used and find out how many square metres each litre will cover.

Divide the square metres of area to be painted by the paints square metre coverage amount, for one coat.

Don’t forget to add the amount of additional coats required to your calculations. For two coats double the amount of paint required, etc. Always add 10-20% for wastage or as I do, don’t minus the doors and windows.


Hint: If you are painting a dark colour, you will require a tinted priming paint and to get a proper cover, up to 3 coats of paint is required. Light colours, only 1-2 coats. Primer may not be used unless painting a light colour over a darker colour.


To calculate area for floor coverings:

When thinking about the type of floor cover to be used, determine how many m2 per room you have so you can get a quote.

Measure each room to be covered in square metres, length by width, add all room measurements together, add an additional 5% to your calculations, then submit this to the carpet shop to get a quote prior to purchasing.

Most places will do an on site professional measure before purchase and installation but it is nice to know what you are up for before hand.


To calculate area for turf or lawn seed:

Weather you are going to turf or use lawn seed to achieve your goal in getting grass down on your new or renovated home, it is nice to know what you are up for.

To do this measure your yard, length x width this will determine how many boxes/bags of seed you will require, or give the area calculations to your turf company for a quote on supply as well as the laying of the turf.

Most rolls of turf are 1 square meter each, 1.7m x 0.6m







To measure area of different or unusual shapes:

To measure the area of a;


Area of a square or rectangle, measure the length x width

Example: length 12m; width 3m

12m x 3m = 36m2


Area of a circle, Measure the diameter of the circled area (side to side through the centre) and multiply by 0.80 then by the diameter again.

Example: diameter 8.5m in width

8.5m x 0.80 = 6.8

6.8×8.5m = 57.8m2 or 56

Hint: a circle is 80% the size of a square.


Area of an oval: Measure length by width of the oval area to be measured, multiply length x 0.80 x width.

Example: Length 14m, width 10m

14m x 0.80×10m = 112m2

Hint: an oval is 80% the size of a square.


Area of a triangle: (equilateral, isosceles, scalene, right, acute and obtuse triangles) To measure the area of a triangle multiply the base x 0.50 x height.

Example: Base 17.5m: height 22m

17.5m x 0.05×22m = 19.25m2

Hint: a triangle is half or 50% the size of a square.


So, what do you think ?