DeckCalculator
Free deck planning tool

Plan the boards before you buy them.

Estimate board rows, stock lengths, fasteners and deck-board cost from your actual dimensions and local prices.

Accurate countsUses actual board width, gap and direction.
Practical cutsIncludes saw kerf and avoids tiny seam pieces.
Local costCompare stock lengths using your own prices.

Deck plan

Top view with board direction, joists and a representative seam.

Area
Boards
Cost
Best value

Enter your project and compare the selected stock lengths.

Stock length comparison

LengthBoardsOverageCost
How it works

Useful math, shown clearly.

DeckCalculator counts rows from board width and gap, accounts for saw kerf, avoids impractically short seam pieces, then compares your enabled stock lengths using the prices you enter.

1. Count rows

Board width plus gap determines how many deck-board rows cover the deck.

2. Build practical seams

Tiny remainder pieces are rebalanced so seam pieces span at least three joist lines.

3. Compare cost

The lowest-cost practical stock-length plan becomes the recommendation.

Free project report

Take the plan to the lumber yard.

Print or save the current calculation as a PDF from your browser.