TrowelMath

How much paint for a 16×20 room?

  • ENERGY STAR sizing · manufacturer bag yields
  • Updated Oct 23, 2026
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16×20 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 × (16 + 20) = 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 320 sq ft per coat (about 1.83 gallons for two coats).

Frequently asked questions

How many gallons to paint a 16×20 room?

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