Paint Calculator
Enter room dimensions, deduct doors/windows, and get paint required in litres or gallons — per coat.
Coverage estimate: 1 L paints ~10 m² (one coat). Add 10% extra for touch-ups.
How the Estimate Works
Wall area = 2 × (Length + Width) × Height, minus door and window area. Then paint = area × coats ÷ coverage (10 m²/L default). The calculator gives results in both litres and US gallons.
Pro Tips
- Buy primer separately — it has different coverage (~12 m²/L).
- Ceilings need a different calc: Length × Width × coats ÷ 10.
- Textured walls: bump coverage down to 7–8 m²/L.
Frequently Asked Questions
How much paint for one room?
A 12×12 ft room with 8 ft ceilings (≈ 36 m² walls) needs ~3.6 litres (1 gallon) for one coat. Double it for two coats.
Coverage per litre?
Most interior emulsion covers 10–12 m² per litre per coat on smooth walls. Textured walls or dark-to-light changes can drop this to 7 m²/L.
How many coats?
Two coats is standard for a uniform finish. Go with three if you're painting white over a deep colour, or over fresh primer on new drywall.
Should I add 10% extra?
Yes — always round up. Spills, uneven absorption, and touch-ups are real. Buy the full can; leftovers help with repairs later.