Paint Calculator
Calculate how many liters of paint you need for walls or ceilings, based on area, number of coats and the paint's coverage.
How to use the paint calculator
- Enter the total wall length (sum of all walls to be painted) and the wall height.
- Enter how many coats you're planning — 2 coats is common when changing color or on a new surface.
- Enter your paint's coverage — check the can, usually 6–10 m² per liter.
How the paint amount is calculated
The calculator works out the area, then divides it by the coverage and multiplies by the number of coats:
To paint 28.8 m² with 2 coats using paint that covers 8 m² per liter, you need 28.8 × 2 ÷ 8 = 7.2 liters.
The surface decides how many coats you need
The coverage printed on the tin assumes an even, primed surface in a colour that does not bleed through. In practice the contrast between the old and new colour decides how many coats are needed: dark over light, or a strong shade over white, generally takes one coat more than the rule of thumb. Strong pigments such as reds and yellows also cover less well than most other colours.
Absorbent surfaces draw paint down into the substrate and noticeably increase consumption. Bare plasterboard, filled surfaces and old dry timber should therefore be primed first — primer costs less per litre than topcoat, gives a more even finish and usually reduces total consumption. This calculator works from area and number of coats; add priming as a separate coat if the surface needs it.
Frequently asked questions
How many coats do I need?
Two coats is standard for most jobs, especially when changing color. If you're painting the same or a lighter color on an already-painted surface in good condition, one coat can sometimes be enough.
Why does coverage vary between paint types?
Coverage depends on the paint's quality, pigment content and the surface's texture. Premium paint products often have higher coverage than budget alternatives.