Paint Coverage Calculator
Calculate gallons of paint needed for any room — including primer, 1-coat, and 2-coat estimates.
Net Wall Area
345
square feet to paint
Coverage Assumption
1 gallon = 350 sq ft per coat on smooth walls. Textured surfaces may require 20–30% more. Primer uses 250 sq ft/gallon coverage rate.
Free Painting Pro Tips
Color selection, prep techniques, and finish guide.
Frequently Asked Questions
How much paint do I need for a room?
Calculate your wall area: add up the perimeter of the room and multiply by ceiling height, then subtract 21 sq ft per door and 15 sq ft per window. Divide by 350 (sq ft per gallon) for one coat. For two coats, double the gallons. Always add 10% for waste and touch-ups.
How many square feet does a gallon of paint cover?
A gallon of standard latex or acrylic paint covers approximately 350–400 sq ft per coat on smooth walls. Textured walls, porous surfaces, and dark colors may reduce coverage to 250–300 sq ft/gallon. Premium paints with higher pigment load often cover better. Always check the manufacturer's coverage rate.
Do I need primer before painting?
Primer is recommended when painting over bare drywall, going from dark to light colors, covering stains or repairs, or painting new wood. One coat of primer typically covers 200–300 sq ft per gallon. Self-priming paints work for minor color changes but may not fully seal bare or repaired surfaces.