PaintCalc

How much paint do I need?

Enter your room size or wall area, coats, and openings to get the gallons of paint you need and the cost. Brand-neutral coverage rates, free, no signup.

Enter your room size or wall area to see how much paint you need.

Paint by room size

10 × 10 room10 × 12 room12 × 12 room12 × 14 room12 × 16 room12 × 20 room14 × 16 room16 × 16 room16 × 20 room20 × 20 room

Paint by wall area

200 sq ft400 sq ft500 sq ft800 sq ft1,000 sq ft1,200 sq ft1,500 sq ft2,000 sq ft2,500 sq ft

Frequently asked questions

How much paint do I need?

Measure the wall area (perimeter × ceiling height), subtract about 21 sq ft per door and 15 per window, multiply by the number of coats, then divide by ~375 sq ft per gallon. A 12×12 room at two coats needs about 2 gallons. Enter your room above for an exact figure.

How many square feet does a gallon of paint cover?

About 350–400 square feet per coat for typical interior wall paint. Economy paint covers around 350, premium around 400. Deep colors, rough textures, and unprimed drywall reduce coverage.

How much paint for a 12x12 room?

A 12×12 room with an 8-foot ceiling has about 384 sq ft of wall. After a door and two windows and at two coats, that is roughly 2 gallons. The calculator adjusts for your exact openings and coats.

Do I need primer?

Prime bare drywall, patched areas, stains, or big color changes (like dark to light). Over an existing painted wall in a similar color, a good self-priming paint usually skips it. Primer is a separate product from your finish coats.