How Much Paint Do You Need for a Room?
Buying paint is guesswork without the coverage maths. Here is how to work out exactly how many litres a job needs.
What is the Paint Coverage Calculator?
Multiply the area to paint by the number of coats, then divide by the coverage per litre stated on the tin. The result is the exact amount needed, and the calculator also rounds it up to whole litres, since paint is sold in full tins and running short mid-wall is no fun.
How to use it
- Enter the total area to paint in square metres.
- Enter the number of coats and the coverage per litre from the paint tin.
- Press Calculate to see the exact litres and the whole litres to buy.
Worked example
Area 53, 2 coats, coverage 10 per litre: the tool gives 10.6 litres exact, rounded up to 11 litres to buy.
How much paint covers 53 square metres with 2 coats at 10 square metres per litre?
You need exactly 10.6 litres, because 53 times 2 divided by 10 is 10.6, so you should buy 11 litres. Rounding up to the next whole litre makes sure you do not run out on the final coat.
Frequently asked questions
Should I subtract doors and windows from the area?
Yes, measure only the surfaces you will actually paint. Subtracting large unpainted areas gives a more accurate result.
Why round up to whole litres?
Paint is sold in whole tins, and a small surplus covers touch-ups, so buying the rounded-up amount is the practical choice.