How Deck Materials Are Calculated
Deck boards run across the width. The number of boards depends on the deck length divided by board width (typically 5.5 inches) plus a small gap between boards.
Joists run perpendicular to boards, spaced 16 inches on center. Each joist needs a hanger at each end. Deck screws are estimated at roughly 350 screws per 100 square feet.
FAQ
How long should deck boards be?
Match board length to deck width when possible to avoid end-to-end seams. Standard lengths are 8, 10, 12, and 16 feet. Longer boards mean fewer joints but more waste from cuts.
Composite vs pressure-treated?
Pressure-treated lumber costs $2–4 per linear foot. Composite decking costs $5–12 per linear foot but lasts longer and needs less maintenance. This calculator gives board counts — costs depend on your material choice.