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Stain calculator

Deck Stain Calculator: How Much Stain Do I Need for a Deck?

Enter your deck and get the exact amount to buy, adjusted for coats, doors, windows, ceilings, and primer. Free, no signup.

Your deck

Advanced

You need

0 gallons
Rounded up to full containers.
Paintable deck area 0
Ceiling area 0
Total area × coats 0
Exact amount needed 0

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How to estimate stain for your deck

Deck stain covers far less than wall paint because wood is porous and the boards have gaps and edges. This calculator defaults to 250 square feet per gallon. Enter your deck length and width as the "room" dimensions and set wall height to the railing height, or set it to zero to estimate the deck floor alone.

Most decks take one to two coats. A semi-transparent stain on smooth, previously sealed wood may reach the high end of coverage, while a first coat on bare, weathered wood soaks up much more, so lower the coverage for a thirsty deck.

Coverage cheat sheet

Surface / situationApprox. coverage per gallon
Smooth, previously stained surface350 to 400 sq ft
New or bare wood / drywall (thirsty)250 to 350 sq ft
Textured, rough, or weathered200 to 300 sq ft
Primer200 to 300 sq ft

This tool defaults to 250 sq ft per gallon for a deck. Change it under Advanced if your surface is rougher or more porous than average.

Frequently asked questions

How much stain do I need for a deck?
A 12 by 12 (144 sq ft) deck needs about a gallon for one coat at 250 sq ft per gallon, and closer to 2 gallons if you add railings and a second coat. Enter your actual size above.
How many coats of deck stain should I apply?
Most deck stains are designed for one to two coats. Bare or weathered wood usually needs two, while a maintenance recoat over sound stain may need just one. Do not over-apply film-forming stains or they can peel.
Why does deck stain cover less than paint?
Decking is horizontal, porous, and often rough or weathered, so it absorbs more product than a smooth vertical wall. Planning for about 250 square feet per gallon keeps you from running short mid-board.

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