Deck Material Calculator
Estimate the materials for a deck. Enter deck size, board dimensions, and spacing to plan boards, joists, and fasteners.
Results
Enter your measurements to see an estimate.
Calculated: — EasyBuildTools, www.easybuildtools.com
How to use the undefined
Enter the deck length and width, then the board width, length, and the gap between boards. Set the joist spacing (16 inches on center is common). The tool estimates deck boards, and gives planning figures for joists, beams, and fasteners. Structural results are for planning only.
Formula and methodology
Deck area = length × width. Board rows = (width × 12) ÷ (board width + gap), rounded up. Boards per row = deck length ÷ board length, rounded up. Deck boards = rows × boards per row × (1 + waste%/100). Joists = (length × 12) ÷ joist spacing + 1. Fasteners ≈ 3.5 per square foot.
Worked example
Deck: 16 ft × 12 ft, 5.5 in boards, 1/8 in gap, 16 in joists, 10% waste, 12 ft boards. Rows ≈ 26, boards per row = 2, with waste 58 boards. Joists ≈ 13. Enter the values above to confirm.
Helpful measurement tips
- Run boards perpendicular to the joists and stagger butt joints.
- Hidden fasteners use more clips than the rough per-square-foot guide.
- Framing spans and footings must follow local code — this tool does not size structure.