How it works
Paint = (wall area − doors − windows + ceiling) × coats ÷ coverage. We take off 1.9 m² (21 sq ft) for each door and 1.5 m² (15 sq ft) for each window, the typical sizes. For big patio doors or bay windows, add an extra door or two.
Tips before you buy
- Going over a dark colour, or painting new plaster? Plan for an extra coat, or a primer or mist coat first.
- Buy all your paint from the same batch so the colour matches.
- Keep a little spare for touch-ups. Our can suggestion already rounds up.
FAQ
How much paint do I need for a room?
Measure the wall area (room perimeter × wall height), subtract doors and windows, multiply by the number of coats and divide by the coverage on the tin. A typical 4 × 3 m bedroom needs about 6 litres for two coats.
How much does a litre of paint cover?
Most emulsion covers about 10–12 m² per litre per coat on smooth, primed walls. Rough, porous or new plaster can drop that to 6–8 m².
How much does a gallon of paint cover?
Usually 350–400 sq ft per coat. Check the can: coverage varies by brand and sheen.