Paint Coverage Calculator (Gallons and Litres)

Net wall area is 2(L+W)H minus 20 ft² per door and 15 ft² per window. Amount = area × coats / coverage.

Inputs

Units

Results

Net wall area: 302.0ft²
Paint / stain: 1.73gal

Recommended gear

HVLP paint sprayer
Faster on large wall areas once the litre count is known.
Typical range: $80–$250
Premium brushes
Cut in after the roller or sprayer.
Typical range: $10–$30

Calculation method

Coverage is an area-per-volume input. In metric mode that area becomes m² and the volume litres, so a 350 ft²/gal can becomes about 8.6 m²/L automatically.

Exact formula

Default coverage 350 ft²/gal (~8.6 m²/L). Two coats is typical on new drywall.

New drywall

Prime first, then two finish coats. Budget more than a repaint on already sealed walls.

Frequently asked questions

Do I paint the ceiling here?

No. This is walls only. Add L×W×coats/coverage separately for a ceiling.

Primer?

Treat primer as another coat with its own coverage, or add a coat.

Why is stain using the same form?

Stain is still area × coats / coverage. Put the stain’s lower coverage in the box.

Disclaimer — no professional advice, no liability

Texture, primer, colour change and brand spread rate all move the number. Read the can.

These calculators, pages and any related content are provided “as is” and “as available”, solely for general educational and informational purposes. They are simplified mathematical estimates, not a construction drawing, cut list or material takeoff, and they do not constitute engineering, architectural, structural, building-code or other professional advice.

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