Deck calculators
Start with the planner for a whole-deck shopping list, or jump straight to the one question you have.
All calculators
Deck Planner
Decking, framing, footings, hardware and concrete in one shopping list, with a plan drawing.
Open →Deck Board Calculator
Boards by stock length with seams placed on joists, plus screws or hidden clips.
Open →Joist Span Calculator
Maximum joist span and cantilever from IRC Table R507.6, and the joist count.
Open →Beam & Post Spacing
Beam size against post spacing from IRC Table R507.5, compared side by side.
Open →Footing Calculator
Footing size from tributary area and soil, plus concrete bags per hole.
Open →Deck Stair Calculator
Risers, treads, stringer length and throat, with a drawing to scale.
Open →Railing & Baluster Calculator
Posts, balusters and rails with every gap kept under the 4-inch sphere rule.
Open →Deck Stain Calculator
Gallons for the deck, railings and stairs, using your product’s label coverage.
Open →Deck Cost Calculator
Budget ranges with named sources, or an itemized cost built from your local prices.
Open →Metric Decking Calculator
m², linear metres and boards by length for UK, Australian and NZ decks.
Open →