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Deck material calculator

Boards are assumed to run the length of the deck. We divide width by board width plus gap, then multiply by length. Waste percent adds extra linear feet and extra boards. This is a takeoff, not a cutting list.

Boards run this direction.

Deck area
192.0 sq ft
Board rows
26
Linear feet
416.00 ft
Linear feet with waste
457.60 ft
Board count (deck-length sticks, after waste)
29

Estimate only. It does not choose 12 ft vs 16 ft stock, stairs, or picture-frame borders.

Deck material calculator example

A 16 × 12 ft rectangle on 5.5 inch boards

Length 16 ft, width 12 ft, 5.5 in boards, 1/8 in gap, 10% waste. You get square footage, how many board rows span the width, linear feet, and a board count after waste.

Deck material calculator how-to

  1. coverageIn = boardWidthIn + gapIn; must be > 0.
  2. boardRows = Math.ceil((widthFt * 12) / coverageIn).
  3. linearFeet = boardRows * lengthFt.
  4. linearFeetWithWaste = linearFeet * (1 + wastePercent / 100).
  5. boardCount = Math.ceil(boardRows * (1 + wastePercent / 100)). Swap length and width if boards run the other way. Not a cutting list.

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Deck material calculator FAQ

How many deck boards do I need for a 12×16 deck?
For a 12×16 ft deck with 5.5 in boards and a 1/8 in gap, boards along the 16 ft length need ceil((12 × 12) / (5.5 + 0.125)) = 26 rows. With 10% waste, board count is ceil(26 × 1.10) = 29 deck-length sticks (about 457.6 linear feet with waste). Swap length/width if your boards run the other way. Estimate only — not a cut list.
How many deck boards do I need?
Boards run along the deck length. First calculate the number of rows: boardRows = ceil((widthFt × 12) / (boardWidthIn + gapIn)). Then multiply by the waste factor: boardCount = ceil(boardRows × (1 + wastePercent/100)). This estimates the total number of full-length boards assuming each stick spans the deck length; it is an estimate only, not a cut list.
Is this an estimate or a cut list?
Estimate only. It ignores stairs, picture-frame borders, actual stock lengths (12 ft vs 16 ft), hidden fasteners, and the way a yard sells mixed packs.
Which way do the boards run?
Along the length field. Width is the direction we tile with (board width + gap). Swap the two numbers if your boards run the other way.
What units?
Deck size in feet. Board width and gap in inches, which matches common 5/4 × 6 decking (about 5.5 in face) and a 1/8 in gap.
Does waste change board count?
Yes. Linear feet are multiplied by (1 + waste%). Board count is the row count increased by the same percentage, rounded up, as if each board is one deck-length stick.
How do I calculate boards without this page?
Boards run along lengthFt. coverageIn = boardWidthIn + gapIn. boardRows = ceil((widthFt × 12) / coverageIn). linearFeet = boardRows × lengthFt. linearFeetWithWaste = linearFeet × (1 + wastePercent/100). boardCount = ceil(boardRows × (1 + wastePercent/100)). Area is length × width in square feet. Estimate only — not a cutting list.