Paint Calculator
Litres of paint and can count for a wall area — by coats, coverage and wastage, minus doors and windows.
This paint calculator estimates how many litres and cans you need for a wall area, based on the number of coats and the paint's coverage. Enter the area to paint, the coats and the coverage per litre to get a litre figure and a can count for your shopping list.
Net paintable area = 400 − 40 = 360 sq ft.
Number of coats
Assumptions — edit to match your site
Coverage is per litre, per coat (emulsion ≈ 10 m²/L). Can size: 1 gallon ≈ 3.6 L; a drum is ~16 L.
= 107.6 sq ft/L
How it's calculated
Net area = (40 × 10) − 40 = 360 sq ft
Litres = 360 × 2 coats ÷ 107.6 sq ft/L × 1.05 = 7 L
Cans = 7 ÷ 3.6 = 2
Indicative estimate only — quantities and prices vary by site, materials and method. Always verify with your contractor or vendor before buying.
How this calculator works
Paint needed = area × coats ÷ coverage per litre. Coverage depends on the surface and paint — 7–12 m² per litre per coat is typical — and the default is editable.
The litre total is divided by the can size and rounded up. New or porous surfaces drink more paint, so a primer coat and a small extra allowance are wise.
Common questions
- How many coats do I need?
- Two coats is standard over a primed surface; strong colour changes or fresh plaster may need a primer plus two coats.
- What coverage figure should I use?
- Check the paint tin — 7–12 m²/litre/coat is common. Rougher surfaces cover less.
Last updated: 8 July 2026
These tools are free
To turn an estimate into reality, hire verified professionals or order materials from suppliers on Mahprotocol.