Enter your Deck Length, Width, Board Size, Joist Spacing, Decking Angle, and Waste Factor into the Deck Board Calculator to find Total Boards Needed, Deck Square Footage, Screws Required, and Linear Feet of Boards — so you can hit the lumber yard fully prepared.
Total Deck Boards Needed
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Deck Square Footage
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Boards Without Waste
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Screws Required
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Linear Feet of Boards
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The number of deck boards needed depends on your deck size, board dimensions, and installation angle. For a standard 12x16 ft deck with 5/4"x6" boards installed perpendicular to joists, you'll typically need around 32-35 boards including waste.
The most common deck board sizes are 5/4"x4", 5/4"x6", 2"x4", and 2"x6". The 5/4"x6" boards are most popular as they provide good coverage while being easy to handle and install.
Besides deck boards, you'll need deck screws or hidden fasteners, joist tape, and possibly additional lumber for rim boards. Plan for 2-3 screws per joist intersection for each board.
Measure the length and width of your deck frame at the outside edges. For irregular shapes, break the deck into rectangles and calculate each section separately, then add the totals together.
90° installation (perpendicular to joists) is standard and uses fewer boards, while 45° diagonal installation creates a more decorative look but requires 15-20% more materials due to cuts and waste.
Plan for 10% waste for straight installations and 15% for diagonal installations. This accounts for end cuts, mistakes, and future repairs. It's better to have extra than run short during installation.
Standard joist spacing is 16" on center for most deck boards. Use 12" spacing for thinner boards or heavy load areas, and 24" spacing only for thicker structural boards following local building codes.