Home & Life · Free tool
Paint Gallons Calculator
Gallons of paint for any room — factors wall count, coats, door/window subtraction, and spread rate.
Updated April 2026
Gallons needed
3 gal
Exact: 2.18 gal — buy 3 gallon(s) to have some in reserve.
Inputs used
Gross wall area: 432 sqft (12 × 9 × 4)
Subtract doors: 1 × 21 sqft · windows: 2 × 15 sqft
Net paintable area: 381 sqft × 2 coat(s) = 762 sqft
Coverage: 350 sqft/gal → 762 ÷ 350 = 2.18 gal
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What it does
Buy the right number of gallons — no second trip to the store.
Runs entirely in your browser — no upload, no account, no watermark. For more tools in this category see the full tools index.
How to use it
- Enter room dimensions.
- Set coats and spread rate.
- Read gallons needed.
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