Home Improvement
Deck stain calculator
Stain runs out at the worst time — halfway through a deck, with the sun moving and half the boards wet. This calculator works from real surface area instead of deck size: the floor, both faces of the railings when you include them, and your coat count, divided by the coverage on your actual can of stain. Most products cover 150 to 300 square feet per gallon, so the label wins; the result is whole gallons to buy and what they cost.
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Deck Stain Calculator
Estimate stain gallons and cost for a deck, including railings and coats.
Inputs used
Results
Rounded up to whole gallons; the can's label wins on coverage.
Additional notes
Your estimate
Results
Rounded up to whole gallons; the can's label wins on coverage.
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Stain & pad applicator kitGallons sorted — pads lay it flat and fast without lap marks.Paid link · Check current price ↗As an Amazon Associate I earn from qualifying purchases.The math, plainly
How it works
- 01
Deck floor area is length × width; railings add roughly 12 square feet per foot of perimeter, counting both faces of rails and balusters.
- 02
Gallons are area × coats ÷ coverage per gallon, rounded up to whole gallons.
- 03
Most stains cover 150 to 300 square feet per gallon depending on product and wood condition — enter your can's coverage and let it override the default.
Try a real scenario
12 × 16 deck with railings
Inputs2 coats, 250 sq ft per gallon
ResultAbout 528 sq ft to stain — 5 gallons, roughly $175 at $35 per gallon.
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More options for this calculator
Pressure washer (paid link)
Stain over gray, dead wood is money on the ground. Wash it, let it dry two days, then stain.
Paint sprayer (paid link)
Rails and balusters are where sprayers earn their keep — brushing forty balusters is a lost day.
Deck cleaner & brightener (paid link)
Cleans and neutralizes the wood so the first coat soaks in evenly instead of patchily.
As an Amazon Associate I earn from qualifying purchases.