Decking board calculator

Estimate decking boards with row counts, board gaps, end cuts and a chosen spare-board allowance.

Processed on your device

How to use this tool

Enter the deck length in the direction the boards will run and the width across the rows.
Enter your board size, row gap and allowance. Run the tool to see boards per row, rows and total boards.

Things to know

One rectangular deck with straight parallel rows. Each row uses its own boards; offcuts are not reused between rows.
End-to-end joints assume no gap. Final rows may need ripping. This is a board estimate; it does not specify joists, fixings or structural support.
Processing stays on your device. Results are not saved between visits.

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