Decking Calculator
How much decking for a deck? Enter the deck size, board width and length, and joist spacing — get boards, joists, footings and screws, with the notes on gaps and code.
Boards run along this dimension.
10% for end cuts and splices; more if boards are short.
Decking for a 192 sq ft deck
29 boards — 451 linear ft · 16-ft boards
Deck area: 192 sq ft (17.8 sq m). Framing: 13 joists at 16-in spacing, about 4 footings (one per 8-ft grid point, as a rough allowance) and roughly 754 screws or clips (2 per joist crossing per board). Check local code for footing depth, ledger attachment and railing requirements before building.
Estimate. Board counts assume boards run the full length with splices where needed; diagonal patterns need about 15% more. Confirm board lengths stocked locally — 20-ft boards are not available everywhere.
Formula used: Linear feet = deck area ÷ (board width + 1/8-in gap, in feet) × (1 + waste%). Boards = linear feet ÷ board length, rounded up. Joists = (deck length in inches ÷ spacing) + 1.
How this estimate works: Decking is bought by the linear foot: the deck area divided by one board's face width (plus the 1/8-inch gap between boards) gives the total board length, and dividing by the stocked board length gives the board count. Joists are counted from the spacing — 16 inches on centre is standard — and the footing count is a rough grid allowance, not a structural design.
How the decking calculator works
Decking is bought by the linear foot: the deck area divided by one board's face width (plus the 1/8-inch gap between boards) gives the total board length, and dividing by the stocked board length gives the board count. Joists are counted from the spacing — 16 inches on centre is standard — and the footing count is a rough grid allowance, not a structural design. Check local code for footing depth, ledger attachment and railing requirements before building, and allow about 15% more for diagonal patterns.
Try next: Drywall Calculator · Insulation Calculator · Fence Calculator
← All 32 tools · Paint guides · Tile guides · Concrete guides