Deck Board Calculator
Enter your deck dimensions and board size to see how many decking boards you need, including a waste factor. The calculator shows the full math so you can drop it straight into a quote.
Decking Boards
Deck area240.0 sq ft
Linear ft (+ waste)576.0 ft
Boards needed36
Material cost$1,008.00
Line total$1,008.00
Deckworks saves the math with the line item so your customer sees exactly how you priced it.
How the math works
- 01Deck area = length × width (in feet).
- 02Linear feet of board = area ÷ (board width in inches ÷ 12).
- 03Add your waste factor — 10% is typical for a square deck, 15% for angles or picture framing.
- 04Boards = linear feet with waste ÷ board length, rounded up.
Common questions
How much waste should I add for decking?
10% covers a simple rectangular deck with square cuts. Go to 15% for 45-degree diagonal layouts, picture-frame borders, or lots of short runs where offcuts pile up.
Does this account for the gap between boards?
Use the actual board width for tight-butted installs. For a 1/8in gap on a 5.5in board, enter 5.625 as the board width and the gap is absorbed into coverage.
What board length should I choose?
Pick the length that spans your deck with the fewest butt joints. A 16ft board on a 12ft deck leaves a 4ft offcut you can usually use on the next row.
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