Deck Calculator
Updated Formulas shown
Boards run parallel to the length you enter. A 16 × 12 ft deck of 5½ in boards needs about 29 boards of 16 ft (with 10% waste) and 13 joists.
Deck boards
29
16 ft boards incl. waste
- Deck area
- 192 ft²
- Rows of boards
- 26
- Joists (16 in on center)
- 13
- Deck screws (2 per joist crossing)
- 710
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Frequently asked questions
How much does it cost to build a deck?
In 2026, pressure-treated decks average $25–$45 per ft² installed and composite decks $40–$70 per ft².
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Estimates only. Check quantities with your supplier or contractor before ordering.