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Deck Material Calculator

Deck boards, joists, footings, and screws from your deck dimensions — with board length, joist spacing, and waste factored in.

Frequently asked

FAQ

How many deck boards do I need?
Divide the deck width by the board face width plus the gap to get the number of rows, multiply by the deck length for linear feet, add ~10% waste, then divide by your board length. This calculator does all of that and rounds up to whole boards.
What does the calculator NOT include?
It estimates field material — decking, field joists, footings, and screws. It does not include the ledger board, rim/band joists, beams, post anchors, footing concrete, stairs, or railing. Add those separately so you don't under-order structural lumber.
How far apart should deck joists be?
16 inches on center is standard. Use 12 inches for a stiffer feel or diagonal decking, and 24 inches only where your decking and local code allow it. The joist count includes a closing joist at each end.

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