How Many Deck Boards for a 12×12 Deck?

A 12×12-foot deck (144 sq ft) laid with standard 5.5-inch boards and a 1/8-inch gap needs about 43 eight-foot deck boards (307 linear feet of decking), including 10% waste for cuts. The calculator below is pre-filled — switch the board length or width to match what your lumberyard carries.

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