AllContraX

Free tool

Paint Calculator

Figure out how many gallons a room needs based on wall area, coats, and openings — before you buy one can too many.

Wall area416 sq ft
Paintable area366 sq ft
Gallons to buy3

Good to know

  • One gallon covers roughly 350 sq ft per coat on smooth, primed walls.
  • Color changes (especially dark to light) usually need two coats plus primer.
  • Ceilings and trim are separate — this calculates walls only.

Want the full picture, not just materials?

Describe the project and get a contractor-style planning estimate — scope, labor, materials, and a realistic range — free.

All free tools

Planning estimates based on standard rules of thumb. Actual material needs vary with site conditions, product dimensions, and installation method — confirm quantities with your contractor or supplier before ordering.