Paint Coverage Calculator

Typically 350–400 sq ft per coat. High-porosity surfaces need more.

Yes — add 10% for trim, edges, and touch-ups.

Perimeter × ceiling height, minus doors and windows.

A 12×12 ft room with 8 ft ceilings has roughly 320 sq ft of wall space after subtracting one door (20 sq ft) and two windows (30 sq ft total). One gallon covers that in one coat. Buy 2 gallons for two coats, plus extra for the ceiling.

A gallon of paint typically covers 350–400 square feet per coat on smooth, previously painted surfaces. Rough textures, bare drywall, and dark-over-light color changes reduce coverage to 250–300 sq ft per gallon.

Two coats are standard for most painting projects. New drywall may need a primer coat plus two finish coats. Dramatic color changes — dark to light or light to dark — often require three coats for complete, even coverage.

Yes. Buy 10% more than your calculation. Keep any leftover paint sealed tightly and labeled with the room and color for future touch-ups. Paint is typically sold in quarts (1/4 gallon) for small quantities.

Flat/matte for ceilings and low-traffic walls. Eggshell for bedrooms and living rooms — some sheen, easy to clean. Satin for kitchens and family rooms. Semi-gloss for bathrooms and trim. Gloss for doors and high-wear surfaces.

Multiply the room length by the width. That's your ceiling square footage. Divide by your paint's coverage rate (usually 400 sq ft/gal for ceilings) and add 10% waste.

Primer seals porous surfaces, improves paint adhesion, and provides a neutral base for accurate color. Use primer on new drywall, bare wood, or when making dramatic color changes. Primer-and-paint-in-one products save a step but rarely match separate primer quality.

Usually yes. Premium paints have higher pigment concentration, often covering in one coat where budget paint needs two. Factor the cost-per-coat, not just cost-per-gallon, when comparing.