Paint Calculator
How many gallons of paint you need
Painting a room or exterior? Enter the total wall length and height, choose your coats, and we'll tell you how many gallons to buy.
How much paint do I need?
A gallon covers about 350 ft² per coat. Add up all wall lengths, multiply by ceiling height, subtract doors and windows, then multiply by coats.
One coat or two?
Plan on two coats for new drywall, color changes, or dark-over-light.
Frequently asked questions
How much does a gallon of paint cover?
About 350 square feet per coat on smooth, primed surfaces. Rough surfaces cover less.
How many gallons to paint a 12x12 room?
Roughly 1.5–2 gallons for two coats with 8-foot ceilings, before deducting openings.