Deck Board Calculator
Boards, linear feet, and screws for your deck surface.
Your estimate
Estimates only. Renovate Cafe's calculators are a planning aid, not professional advice — double-check your inputs, confirm coverage on the product you buy, and verify quantities and local code for structural, electrical, or permitted work. Disclaimer.
Give Renovate Cafe your deck's footprint and the boards you're using. You'll get the number of boards (with waste), the rows across the deck, total linear feet, an estimate of screws, and the cost.
How many deck boards do I need?
Decking is laid in rows across the deck. Each row takes up its board width plus the gap you leave for drainage and expansion. Divide the deck length by that combined spacing and you have the number of rows. Each row spans the deck width, so rows × width is your total linear feet of decking.
Boards come in fixed lengths — 12, 16, and 20 feet are common. The calculator divides your linear-foot total by the board length you chose, rounds up, and then adds a waste factor. Ten percent is right for a standard straight layout; bump it to 15% for diagonal decking or a picture-frame border, where the angled cuts waste more material.
Gaps, screws, and a buying tip
Leave a gap of ⅛ to ¼ inch between boards. Pressure-treated wood is often wet when you buy it and will shrink as it dries, so gap on the smaller side and let it shrink open. Composite is dimensionally stable — follow the maker's gap spec exactly.
For fasteners, plan on roughly 350 deck screws per 100 square feet, or about two screws at every joist crossing. The calculator estimates screws from your board count. Buy a box more than you think you need; running out of the right color screw three rows from the end is its own special frustration.
Frequently asked questions
How do I calculate deck boards?
How much gap between deck boards?
How many screws per deck board?
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