How much paint will I need?
Multiply the wall area by the number of coats, then divide by how far a litre stretches. Coverage varies with the paint and surface — smooth interior walls might get 110–130 square feet per litre, rough or porous surfaces much less. A first coat on fresh plaster always soaks up more, so round up and keep a little spare for touch-ups.
Frequently asked questions
What coverage should I use?
Check the tin — most give a coverage figure. As a rough guide, one litre of emulsion covers about 10 square metres (110 sq ft) per coat on a smooth wall.
Should I subtract doors and windows?
For a tighter estimate, yes. For small rooms it's often easier to leave them in as a built-in safety margin.
How many coats do I need?
Two is typical. Dark colours over light, or light over dark, may need three.