Deck Calculator
Estimate decking boards, joists, support posts, fasteners, and concrete.
Preparing your calculator…
How this calculator works
Board rows = ceiling(deck width in inches ÷ (board width + gap)). Multiply by deck length for decking linear feet. Joists use ceiling(length in inches ÷ joist spacing) + 1. Support posts use an editable rectangular grid, concrete uses cylindrical footings, and fasteners assume two screws at every board/joist intersection.
Use current quotes, local rates, and measured dimensions to make this estimate useful for your situation.
Frequently asked questions
Is this a structural deck design?+
No. Local code, spans, loads, connections, wood species, soil, and frost depth require separate design or engineering review.
What if boards are shorter than the deck?+
The result is full-length board rows and total linear footage. Divide and plan joints based on actual stock lengths, support positions, and manufacturer requirements.