Construction Calculators
Deck Material Calculator for Boards & Joists
Estimate deck boards, decking linear feet and joists from your deck size, board dimensions, spacing and waste.
Quick answer: Enter the deck length and width, choose a board size and joist spacing, then tap Calculate. The result shows full boards to buy, decking linear feet, joist count and deck area.
Inputs
Materials
Fill the form and press Calculate.
Deck material calculator FAQ
What does this deck material calculator estimate?
It estimates deck area, decking linear feet, full boards to buy and joist count from the values you enter.
How does the calculator work out deck boards?
It uses deck area and the selected board width to calculate decking linear feet, adds the waste percentage, then divides by the selected board length and rounds up.
How does joist spacing affect the result?
Closer on-centre spacing produces more joists. This calculator spaces joists across the deck width and uses the deck length as each joist length.
Does this estimate include posts, footings, stairs or fasteners?
No. Those items are not inputs in this calculator. Use the linked concrete, stair and baluster tools where they match your project, and plan hardware separately.
How does the waste percentage affect the board count?
The calculator adds the selected waste percentage to decking linear feet before dividing by board length and rounding up to full boards.