Paint Calculator

Paint gallons needed for walls and ceilings — with coat count and doors/windows deduction.

Calculator Construction Updated Apr 19, 2026

Perimeter (ft) Wall height (ft)

Doors (21 ft² each) Windows (15 ft² each) Coats

Include ceiling Coverage (ft²/gal)

Notes

Coverage

~350 ft² / gal typical

Porous surface

Drop to 250 ft²/gal (new drywall)

Primer

Add 1 gal primer per 400 ft² of new surface

Last updated: April 19, 2026