Figuring out how much paint to buy usually means measuring walls by hand, guessing at how much doors and windows subtract, and second-guessing whether one can is enough for two coats. Our paint calculator does the math for you:
- Instant — gallons and paintable area update as you type, with no page reload.
- Openings-aware — enter your door and window counts and we subtract their typical area automatically, so you’re not paying for wall space that isn’t there.
- Coats included — set how many coats you’re planning, and the gallon count adjusts to match, instead of assuming a single pass.
- Honest about coverage — 350 sq ft per gallon is a common manufacturer figure for smooth, primed walls, and we say so plainly rather than treating it as an exact number. Textured or unprimed surfaces will use more.
Try it with your own room dimensions, and if you write about home projects, the calculator is embeddable on your own site with one iframe.