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quarts (if sold by quart)
Stain Coverage Calculator
Find out how much stain, polyurethane, paint or oil your project needs — enter the surface area (or its size), pick a finish and the number of coats. Imperial or metric. Nothing is uploaded.
Your project
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Units
Area input
Include every face you'll finish. A 4×8 sheet, one side, is 32 sq ft.
Result
Finish needed0
gallons
Buy 1 quart
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total area to coat
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gal per coat
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estimated cost
Coverage varies with wood porosity and application — buy a little extra rather than run short mid-coat.
How much finish you really need
The math is straightforward: (area × coats ÷ coverage per gallon) + waste. The catch is coverage — it changes a lot by product. Wood stain spreads around 200 sq ft per gallon, polyurethane is thicker at 125–150 sq ft, latex paint reaches ~350 sq ft, and penetrating oils soak in fast at 100–150 sq ft. Bare, porous or end-grain-heavy wood drinks up the first coat, so the real-world figure is usually toward the low end. We add a waste allowance (10% by default) for soak-in, drips and touch-ups.
How much does a gallon of stain cover?
About 200 sq ft per coat for typical wood stain. Polyurethane covers 125–150, paint about 350, and oils 100–150 — porous wood reduces all of these.
Do I count both sides?
Yes, if you're finishing both faces and the edges. Switch to "By size" and choose 2 faces, or add the extra area into the total.
Sizing the lumber too?
Work out board feet and cost with the board foot calculator, or compare species in the wood hardness chart.