Free deck board and fastener calculator. Enter deck dimensions, board size, gap, and joist spacing to get the exact number of boards, screws or hidden clips, and total material cost.
Use when quoting materials for a new deck build, including the fastener count that most board-only calculators skip.
Most decking calculators give board count only. This one adds fastener totals so the hardware run isn't a separate trip.
Rows across the deck width = (deck width in inches) ÷ (board width + gap), rounded up so the last row still fits.
Boards per row = deck length ÷ available board length, rounded up to whole boards since every board must end on a joist.
Joist crossings = joist count × rows, and each crossing needs 2 screws or 1 hidden clip; total cost sums linear footage of decking plus every fastener.
The default 3/16-inch gap lets water drain through the deck surface instead of pooling, and gives the boards room to expand and contract with humidity and temperature. Too tight a gap can cause cupping or buckling; too wide wastes boards and can catch heels or debris.
Screws are cheaper per unit, faster to install without special tools, and easy to replace a single board later, but leave visible fastener heads. Hidden clips give a clean, fastener-free surface and slightly reduce trip hazards, but cost more per unit and this calculator assumes only one clip per crossing versus two screws.
Whenever a board doesn't span the full deck length, its end must land on a joist so it's properly supported — that's why this calculator rounds boards-per-row up to whole boards rather than assuming boards can be trimmed to fit perfectly. Planning your board lengths against your joist layout in advance minimizes awkward short offcuts.
입력
16×10 ft deck, 5.5" boards, 3/16" gap, 16 ft boards, 16" joist spacing, screws, $2.00/ft boards, $0.10/screw.
출력
22 boards, 572 screws, $761.20.
Rows = ceil((10×12)/(5.5+0.1875)) = 22. Boards per row = ceil(16/16) = 1, so 22 boards total using 352 linear ft. Joists = ceil((16×12)/16)+1 = 13. Fasteners = 22 rows × 13 joists × 2 screws = 572. Cost = 352×$2.00 + 572×$0.10 = $704 + $57.20 = $761.20.