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.
⚠ Disclaimer
This calculator provides material quantity estimates for planning. Deck construction must comply with local building codes, which specify requirements for footings, ledger attachment, railing height, stair dimensions, and load capacity. Most jurisdictions require a building permit for deck construction. Consult a licensed contractor or your local building department before starting.
Related Calculators
- Concrete Calculator — concrete for deck footings and piers
- Fence Material Calculator — posts, rails, and pickets for a deck railing or yard fence
- Paint Coverage Calculator — for staining or painting your deck surface
- Gravel Calculator — gravel base under deck footings and drainage