How to use the Paint Calculator
Enter the room size, number of doors and windows, and the paint's coverage (printed on the tin, usually per litre per coat). The calculator works out the area and the litres needed.
Coverage varies by brand, product and surface texture. Rough or new plaster absorbs more paint — always buy a little extra from the same batch.
Frequently asked questions
How much area does 1 litre of paint cover?
Typically 80–140 sq ft per coat for interior emulsions, depending on the product and surface. Check the label.
How many coats do walls need?
Usually two coats of paint over primer for new walls, one or two for repainting the same colour.