Deck Calculator
Use this deck calculator to estimate deck area, materials or board requirements. Enter deck length, width, board size and spacing and review an estimated deck area and material quantity.
Deck boards needed (with 10% waste)
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Deck area —
Joists —
Screws (approx.) —
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How it works
Boards = deck width ÷ (board width + gap) × waste; joists = length ÷ spacing + 1How to use the Deck Calculator
Start by entering deck length, width, board size and spacing. Keep the units consistent and check that each value belongs to the same question.
The result gives an estimated deck area and material quantity. Allow for framing, waste, cuts and local building requirements. Use it as a guide and check any instructions, rules or professional advice that apply.
Frequently Asked Questions
What does this deck calculator calculate?
It gives an estimated deck area and material quantity. Allow for framing, waste, cuts and local building requirements.
What information should I enter?
Enter deck length, width, board size and spacing. Use the same units throughout so the result is easier to understand.
Should I add extra material?
Yes. A small allowance for cuts and waste can help, but the amount depends on the layout.