basic

Room Paint Coverage in Gallons Calculator

Gallons = paintable area / coverage rate.

Estimate the gallons of paint needed for a room: compute wall area = 2(L+W)×H − door & window area, then divide by coverage rate (default 350 sqft/gal). Reports gallons for one coat, two coats, and full ceiling coverage. Recommends rounding up to the nearest half-gallon.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

ft
ft
ft
sqft
sqft/gal

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

Gal = area / coverage_rate × coats.

In depth

Estimate the gallons of paint needed for a room: compute wall area = 2(L+W)×H − door & window area, then divide by coverage rate (default 350 sqft/gal). Reports gallons for one coat, two coats, and full ceiling coverage. Recommends rounding up to the nearest half-gallon.