Paint Calculator (Square Footage)
Calculate paint coverage for any room. One gallon covers about 350 sq ft for one coat on smooth surfaces — and most projects need two coats.
Paint Calculator
Paint coverage explained
Most quality interior latex paints rate at 350 to 400 sq ft per gallon for one coat on smooth, sealed drywall. That number drops on porous, textured, or unprimed surfaces.
For most rooms you'll do two coats. Plan for around 175 sq ft of finished wall per gallon. A 12×14 room with 8 ft ceilings (about 416 sq ft of wall) needs around 2.5 gallons for two coats — round up to 3.
When to add primer
New drywall, dramatic color changes (dark to light), stain coverage, and high-gloss surfaces all benefit from primer. One gallon of primer typically covers 300 sq ft.
Skip primer only when you're repainting a similar color over an existing finish in good condition.
Pro tips
Buy by the gallon
Even if you need 1.3 gallons, buy 2. Color batches vary; matching mid-project is risky.
Subtract doors and windows
A standard door is ~21 sq ft, a standard window ~15 sq ft. Subtract these from your wall total.
Two coats > one thick coat
Two thin coats always look better and last longer than one thick coat.
Buy from one batch
Specify the same batch number when buying multiple gallons. Slight color variations between batches are common.