Deck Dimensions
Decking Material
Substructure
0
Total Area (Sq Ft)
0
Deck Boards
+10% waste
0
Joist Material (Linear Ft)
0
Deck Screws
+10% waste
Estimating the right amount of materials for a deck prevents unnecessary trips to the hardware store and ensures you don't overspend. The calculation starts with finding the total square footage of your deck by multiplying the width by the depth.
For the decking boards, the calculation depends on the width of the boards you choose. Standard 6-inch decking boards are actually 5.5 inches wide. When calculating the total linear feet of decking required, you must also factor in a standard 1/8-inch gap between boards for drainage and expansion. Our calculator handles this complex math automatically, converting the total linear feet into the exact number of boards you need based on your preferred board length.
Joists are the structural support members that run underneath your decking. The spacing between joists (measured "on center" or O.C.) determines how stiff and strong your deck will feel. Common spacing options include 12", 16", and 24".
When purchasing building materials, it is an industry standard to add a 10% waste factor to your final count. This calculator automatically includes a 10% buffer for your decking boards and screws. You will inevitably make imperfect cuts, find boards with bad knots or warping, or simply drop screws through the cracks of the deck. Buying exactly what the math dictates almost always guarantees you will run short before the project is completed.
📚 Complete Guide
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