How much paint do I need?

Multiply your wall area by the number of coats, then divide by the coverage of the paint, usually around 10 square metres per litre. Most walls need two coats, and bare or dark surfaces may need more. The calculator turns that into litres and cans.

How do I measure wall area?

Add up the length of all the walls and multiply by the height. You can subtract large windows and doors, roughly 1.5 to 2 square metres each, if you want a tighter estimate. For a quick result, enter the total wall area you measured.

How many coats of paint?

Two coats is standard for a good finish over an existing painted surface. New plasterboard usually needs a sealer or undercoat first, and strong colour changes can need an extra coat. Set the number of coats to match your job.

Paint Calculator

Work out how much paint to buy. Enter the total wall area, the number of coats, and the paint's coverage, and the calculator shows the litres you need and how many 4 litre and 10 litre cans that is. If you do not know the area, multiply the total length of your walls by their height.

Wall area (m²)

Coats

Coverage (m² per litre)

0 L

paint needed

10 litre cans0

4 litre cans0

Buy a little extra for touch-ups. Bare or dark surfaces may need an extra coat.

How it works

The paint needed is the wall area times the number of coats, divided by the coverage. Coverage is usually about 10 square metres per litre on a smooth painted wall, but rough or porous surfaces soak up more, so the litres go up.

Worked example

For 60 square metres of wall at two coats and 10 square metres per litre, you need 60 times 2 divided by 10, which is 12 litres. That is two 10 litre cans, or you could buy one 10 litre and one 4 litre to have a little spare.

Related calculators

Square Metre Calculator: work out an area.
Wallpaper Calculator: rolls of wallpaper.
Tile Calculator: tiles for a surface.
Plasterboard Calculator: sheets for a room.

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