How this deck board calculator works
The calculator divides your deck area by the effective width of one board — the board itself plus the gap — to get total lineal footage, adds waste for cuts and culls, and divides by your board length to get a board count. A standard 5/4×6 deck board is 5.5 inches (140 mm) wide, and the usual gap is ¼ inch (6 mm) for drainage and expansion.
Choosing board length and layout
Buy boards that span the full deck width when possible — fewer butt joints look better and last longer. If the deck is longer than available boards, plan joints to land on joists and stagger them between rows. Running boards diagonally looks sharp but adds about 15% waste; enter that in the waste field.
Fasteners and framing
Plan about 3.5 screws per square foot — two screws per board at every joist on 16 inch (40 cm) centers. Hidden fastener systems use roughly one clip per square foot instead. This calculator covers the decking surface only; the frame (joists, beams, posts, hardware) is a separate list that depends on your span and local code.