How to use the Paint Calculator
- Measure the paintable surface and subtract large openings first.
- Enter coats, manufacturer coverage, container size, and waste.
- Use the rounded container result when purchasing.
How the calculation works
Paint volume = area × coats × (1 + waste) ÷ coverageTotal coat area is adjusted for waste, then divided by the coverage stated on the paint product. Whole containers are rounded up.
Example calculation
An 80 m² surface with two coats and 10 m²/L coverage needs 16 L before waste. With 10% waste, the estimate is 17.6 L, so four 5 L cans are required.
How to interpret the result
Porous, textured, previously unpainted, or high-contrast surfaces may use more paint than the label coverage suggests.
Notes and assumptions
- Surface area already excludes doors and windows as appropriate.
- Coverage and container size use the selected measurement system.
- Primer and specialty coatings are calculated separately.
Common questions
Paint Calculator questions
Should I include two coats?
Enter the number recommended for the surface and product; many projects use two finish coats.
Why round containers up?
Paint is sold in fixed container sizes, so a partial calculated container still requires a full purchase.
Is primer included?
No. Calculate primer separately using its own coverage rate.