Estimate deck boards, joists, screws and total cost for your backyard deck.
Boards: Deck area ÷ (board width + gap) ÷ board length. Standard 5/4×6 decking is actually 5.5 inches wide.
Joists: With boards running the deck length, joists = ceil(deck length ÷ joist spacing) + 1. Rotate the orientation if your framing plan differs. Use 2×8 or 2×10 lumber for 16" spacing.
Screws: ~350 screws per 100 sq ft (2 screws per joist per board).
| Material | $/sq ft | 12×16 Deck | Maintenance |
|---|---|---|---|
| Pressure-treated | $2-3 | $400-600 | Annual seal |
| Cedar | $3-5 | $600-1000 | Every 2-3 yrs |
| Composite | $4-8 | $800-1600 | None |