Resources · 4 min read
Buying too much or too little paint is frustrating. Here's a simple method to estimate the quantity you need and avoid nasty surprises.
1. Work out the surfaces
Measure the wall area: the room's perimeter × height. Subtract large openings (doors, windows). For the ceiling: length × width.
2. Account for the coverage
Every paint states a coverage, often 10 to 12 m² per litre per coat. Divide your surface area by the coverage to get the litres per coat.
3. Multiply by the number of coats
Most jobs call for two coats (plus an undercoat on new or dark surfaces). So multiply your result by the number of coats planned.
A worked example
For 40 m² of walls, at 11 m²/L and 2 coats: 40 ÷ 11 × 2 ≈ 7.3 litres. Allow a small margin for touch-ups.
The easiest way: our estimator
Rather than working it all out, our online estimator gives you a price range directly from your surfaces.
A painting project in Geneva?
Estimate your work online or request a free, no-obligation quote.
Frequently asked questions
Do you always need two coats?
Most often yes, for a uniform result — especially when changing colour.
How can I estimate without measuring everything?
Use our online estimator: it calculates from the surfaces you enter.