Deck Board Calculator
Calculate how many deck boards you need based on deck dimensions, board width, and spacing.
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How to Calculate Deck Boards
Divide deck width (in inches) by board width plus gap to get number of boards. Multiply by the number of runs if boards are shorter than deck length. Add 10% for waste and cuts.
Frequently Asked Questions
How many deck boards do I need for a 12x12 deck?
For a 12x12 foot deck using standard 5.5-inch wide boards with 1/8-inch gaps, you need approximately 26 boards at 12 feet long. With 10% waste, buy 29 boards.
What is the gap between deck boards?
Standard gap is 1/8 inch for wood boards and 3/16 inch for composite. This allows for drainage and expansion.