Paint Calculator

Measure wall perimeter × ceiling height for total wall area, subtract doors and windows, then divide by coverage (400 sq ft/gallon for smooth walls) and multiply by number of coats. Example: 12×14 room, 8-ft ceilings = 416 sq ft walls − 51 sq ft openings = 365 sq ft. Two coats ÷ 400 = 1.8 gallons — buy 2.

One gallon covers about 350–400 sq ft per coat on smooth, primed drywall. Textured walls get 250–350 sq ft. Porous surfaces get 200–300 sq ft. These are planning numbers — always buy slightly more than calculated.

Yes on new drywall, patched areas, bare wood, and when painting light over dark. Primer seals the surface and reduces coats needed. One gallon of primer covers about 350–400 sq ft — similar to paint.

DIY material cost for an average bedroom runs $60–$150 for paint and supplies. Professional painters charge $350–$850 per room including labor. Our calculator shows both material-only and installed estimates.

Two coats is standard for color changes on primed walls. One coat may suffice when refreshing the same color. Dark or saturated colors on white walls often need a primer coat plus two finish coats.

Include the ceiling if you plan to paint it — ceiling area equals room length × width. Ceilings typically use flat white paint. Most homeowners repaint walls more often than ceilings.

Flat hides imperfections and is fine for low-traffic ceilings and bedrooms. Eggshell and satin are washable and standard for living rooms, hallways, and kitchens. Semi-gloss for trim, doors, and moisture-prone areas.

Latex paint is usually dry to touch in 1–2 hours and ready for a second coat in 4 hours. Wait 24 hours before hanging pictures or moving furniture against walls. Cool or humid conditions extend drying time.