Board layout, picture framing, stairs, and breaker boards can change the count.
Decking
Deck Board Calculator
Enter deck dimensions and board specs to calculate deck surface area, board rows, boards, and fasteners.

Calculation method
How the estimate is built.
Deck length and width give the surface square footage. Board face width plus gap determines rows across the deck, stock-board length determines boards per row, waste rounds material up, and fasteners estimate two at each joist crossing plus the same buffer.
Field notes
Use the estimate well.
Composite decking often has manufacturer-specific spacing and fastening rules.
Buy compatible screws or hidden fasteners for your board material.
FAQ
Deck Boards questions
How many deck boards do I need?
The count depends on deck width, board face width, gap, board length, and waste. This calculator estimates straight runs.
Does this calculate framing lumber?
No. It estimates surface boards and fasteners, not beams, joists, posts, stairs, or railing.
How do I calculate deck square footage?
Multiply deck length by deck width. This calculator also uses board width, gap, board length, and waste to turn that surface area into board and fastener estimates.