Deck Board Calculator
Estimate decking surface rows and linear footage from the deck dimensions, actual board face width, board gap and optional board length.
Decking Material & Board-Direction Preview
Compare a conceptual wood, composite or PVC surface and see how rotating the same rectangular decking field can change row count and theoretical linear feet. The preview does not design or approve the supporting frame.
Gray composite look. Actual cap, grain, sheen and color vary by product and lighting.
Direction comparison from the calculator inputs
Enter the actual board face width in the calculator above. This comparison reuses those measurements and your explicit waste allowance.
Material/system checks
Continue your project estimate
Estimate deck project cost →What this deck board calculator estimates
The tool estimates the decking surface only. It determines how many board rows fit across the deck width, multiplies those rows by the board-run length, then applies any extra percentage you choose.
rows = ceiling(deck width ÷ effective board width)
decking linear feet = rows × deck length
Why framing is excluded
Substructure is a safety-critical design problem, not just a material-count problem. Trex separates deck dimensions, substructure, decking and railing in its own planning workflow and describes the framework as critical to safety. This calculator therefore does not size joists, beams, posts or footings.
About the whole-board estimate
If you enter a stock board length, the calculator converts purchase linear footage into a minimum whole-board count. Seam layout, stagger requirements, board defects and unusable offcuts can increase the real quantity, so verify the result against the final board layout before purchasing.
Related calculators
Deck-board quantity is separate from structural framing
The board layout can estimate rows, linear footage and whole boards, but it does not size joists, beams, posts, footings or connections. Structural requirements depend on span, loads, species or product, fasteners, local conditions and applicable code.
For decking purchases, confirm the actual board width, gap and available stock length. Direction changes, picture-frame borders, stairs and breaker boards can add material beyond a simple rectangular field. Keep those design details explicit instead of increasing the deck dimensions to hide them.
Example: plank direction changes minimum board quantity
Imagine a simple 12 × 10 ft rectangular deck field and a decking product with a measured 5.5-inch face width and a chosen 1/4-inch gap. If the boards run along the 12 ft dimension, ceiling(10 × 12 ÷ 5.75) = 21 rows, requiring a theoretical 21 × 12 = 252 linear ft. Rotating boards to run along the 10 ft dimension gives ceiling(12 × 12 ÷ 5.75) = 26 rows, or 260 linear ft before cuts.
The difference does not include border boards, stair treads or non-reusable offcuts. Even if the calculator indicates a whole-board minimum, actual stock lengths and joint placement can change the purchasing plan. The correct board gap and fastening instructions must come from the chosen decking product.
Before buying decking boards
Board quantities change with stock lengths and installation specifications. Compare whole-system wood, composite and PVC purchasing decisions after sizing the layout.