Home & Garden
Paint Calculator
Estimate paint from a known area or measure walls directly. Add walls, subtract doors and windows, include a ceiling, then calculate litres to buy.
Coverage varies by paint brand, surface, colour change and application method. Check the tin before buying.
Useful notes
Should I subtract doors and windows?
Yes, if you want a closer estimate. Use measure mode, add each wall, then remove doors and windows as cut-outs.
What paint coverage should I use?
Use the coverage printed on the paint tin. Ten square metres per litre is a common default, but it varies.
Notes and next steps
How it works
Estimate how many litres of paint to buy from measured wall area, coats, coverage and waste allowance.
Estimating method: Base litres = paintable area × coats ÷ coverage per litre. Litres to buy = base litres × (1 + waste percentage ÷ 100).
Worked example
36 m², 2 coats, 10 m²/L and 10% waste needs 7.92 L, so buy at least 8 L.
Common mistakes
- Not checking coverage on the tin.
- Forgetting extra coats for dark colour changes.
- Not subtracting large doors or windows.