BuildRuler

Build & DIY estimates

How much paint for a 18×18 room?

  • Manufacturer bag yields · published coverage rates
  • Updated
  • Reviewed by Alex · How we calculate

18×18 room: paint by wall height

Wall heightPaintable sq ftGallons (2 coats)Buy
8 ft5263.014
9 ft5983.424
10 ft6703.834

1 door and 2 windows deducted; 350 sq ft per gallon.

Worked example

Perimeter: 2 × (18 + 18) = 72 ft. With 8 ft walls: 576 sq ft, minus 20 (door) and 30 (two windows) = 526 sq ft. Two coats: 1052 ÷ 350 = 3.01 gallons. The ceiling adds 324 sq ft per coat (about 1.85 gallons for two coats).

Frequently asked questions

How many gallons to paint a 18×18 room?

About 3.01 gallons for two coats on 8 ft walls (buy 4).