Project category

Painting Calculators

Estimate wall paint quantity from room dimensions, coats, coverage per gallon, and optional door and window deductions.

Tools

Painting calculators

Open a calculator to adjust dimensions, material size, waste factor, assumptions, and optional user-entered unit price.

Estimate finish paint for rectangular room walls using coats, label coverage, openings, and waste. Optionally estimate primer separately using its own coats, coverage, and user-entered price.

Worked examples

Use these scenario pages when your project is close to a common size, then edit the embedded calculator inputs.

Painting How Much Paint for a 12x12 Room?

This example embeds the paint calculator with a 12 ft by 12 ft room, 8 ft walls, and two coats.

When to use these tools

Estimate wall paint for bedrooms, offices, living rooms, and small remodels.
Adjust for paint coverage, number of coats, and large openings.
Add an optional primer estimate with its own coats and product-label coverage.
Round liquid volume to a practical whole-gallon equivalent.

Common inputs

Room width, room length, and wall height.
Number of coats and coverage per gallon from the paint label.
Optional door and window counts for rough area deductions.

FAQ

Do painting calculators include primer?

The Paint Calculator can estimate primer separately when you select Include primer and enter primer coats and product-label coverage.

Why does the result show a whole-gallon equivalent?

Paint is usually purchased in container sizes, so the calculator shows estimated liquid volume and a rounded whole-gallon equivalent.