How Much Paint Do You Need?
Calculate gallons of paint needed for any room. Enter dimensions, number of coats, and get the exact amount with cost estimate.
How to Calculate Paint Coverage
One gallon of paint covers approximately 350-400 square feet on smooth walls. Calculate your wall area: perimeter × height, then subtract doors (~21 sq ft each) and windows (~12 sq ft each). Standard rooms need 2 coats for full coverage — multiply the area by 2. Always round up to the nearest gallon.
When You Need More Paint
Textured walls, porous surfaces (new drywall), and dramatic color changes (dark to light or vice versa) reduce coverage to 250-300 sq ft per gallon. A primer coat before the finish color saves paint and produces better results when making large color changes.
Paint Quality Matters
Premium paints ($50-70/gallon) offer better coverage (often one-coat), more durable finish, easier application, and better color accuracy than budget paints. The difference between a $28 gallon and a $60 gallon is often only $60-120 for a whole room — a small price for significantly better results that last years longer.
Benjamin Moore and Sherwin-Williams premium paints cover 400+ sq ft per gallon vs 300 sq ft for budget paints. At 2 coats on a 12×12 room, premium requires 2 gallons ($120) while budget requires 3 gallons ($84) — premium is only $36 more and looks significantly better.
