How Much Primer Do I Need?

Primer prepares walls for paint and helps with adhesion. Primer covers 200-300 sq ft per gallon — less than paint because it soaks into the surface.

Room Dimensions

Length (ft)

Width (ft)

Height (ft)

Walls to Paint

Doors & Windows

Doors

Windows

Paint Details

Number of Coats

Coverage (sq ft / gallon)

Standard: 350 — no need to change unless your paint can says otherwise

Enter your room details and click Calculate.

How This Paint Calculator Works

Our calculator uses your room's length, width, and height to calculate the total wall area. It then subtracts space taken up by doors (about 21 sq ft each) and windows (about 15 sq ft each). Finally, it divides the paintable area by the coverage rate of your paint (typically 350 sq ft per gallon) and multiplies by the number of coats you need.