Home Improvement
Deck board calculator
Deck board counts are a row problem, not an area problem: rows come from board width plus gap spacing across the deck, and linear feet come from rows times the run. Enter your deck dimensions, board width, gap, stock length, and a waste allowance to get rows, total linear feet, and whole boards to buy. The fastener note keeps screws honest — two per joist crossing, planned from your joist layout, not from the deck's area.
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Deck Board Calculator
Count deck board rows, linear feet, and whole boards to buy from deck size, board width, and gaps.
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Deck screw kitBoards counted — two fasteners per joist crossing adds up fast.Paid link · Check current price ↗As an Amazon Associate I earn from qualifying purchases.The math, plainly
How it works
- 01
Rows are the deck width in inches divided by board width plus gap, rounded up.
- 02
Total linear feet is rows × deck length — set length as the direction your boards run. Waste covers crosscuts, defects, and butt joints.
- 03
Boards to buy is linear feet with waste divided by your stock length, rounded up to whole boards.
Try a real scenario
12 × 16 deck
Inputs6" boards, 1/8-in gaps, 12-ft stock, 10% waste
Result35 rows, about 420 linear ft, and 39 twelve-foot boards.
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More options for this calculator
Circular saw (paid link)
Crosscutting 39 boards by hand is nobody's weekend. A sharp blade pays for itself in an afternoon.
Joist tape (paid link)
One roll over the joists stops rot where the screws go through — the cheapest years a deck gains.
Speed square (paid link)
Straight gap lines, square ends, and a saw guide in one flat piece of metal.
As an Amazon Associate I earn from qualifying purchases.