Paint calculator

If you need to calculate the area of an odd-shaped room, simply follow these steps:

• First measure the height and width of each rectangular section to be painted. Multiply these figures to get the area, then add them together for the total area.
• A stairwell often forms a triangular shape. For the area of a triangle, multiply the lengths of the horizontal and vertical legs and divide by two.

Top quality paints not only give you easier and better coverage but are longer lasting and easier to clean than low-grade paints. Budget for the best – it pays in the long run. Similarly, good quality paint brushes and rollers will give you a better finish.

If you plan to paint the trim a different colour, calculate these areas separately. Simply multiply the length by width of each trim then add your totals together.

A skirting board area is its height multiplied by its length (which is generally the same as the perimeter of the room).

Estimating time brings in a new set of variables. In 1 hour, you're likely to cover about 7 square metres of an ordinary surface, or about 5 square metres of bare wood or plaster.

You'll probably be able to paint that 4m x 5m room with one coat in 5–6 hours. If you apply 2 coats, you must allow time for the first coat to dry. Allow 4 hours for water-based paint and overnight for oil-based paint (check the paint can label). You can safely estimate 2–3 days to paint a room and clean up afterwards.