Quick answers from the same span tables and designer the 16Span planner uses, under your province's Part 9 rules (Ontario unless you pick another) or the US IRC 2021. They run in your browser, instantly.
Which joist sizes span your distance at 12, 16 or 24 in on center, with the margin and maximum cantilever.
Span · spacing · speciesThe beam, how many posts and footings, how far apart, and how big, for a deck of your size and height.
Size · height · attachedAn estimated materials total for your deck and where the money goes, at big-box prices.
Size · height · deckingWhere these numbers come from. The deck's guard, footing depth and post size follow the Ontario Building Code 2024, Part 9, with its article numbers. Member sizes and footing diameters use US prescriptive tables (IRC 2021 Section R507, No. 2 lumber at 40 psf live and 10 psf dead load) until licensed Canadian tables are added; confirm them with your building department. Those table values are still being checked line by line against the code book. Snow: the calculator doesn't know your town, so it uses Part 9's minimum deck load of 1.9 kPa (40 psf) (OBC 9.4.2.3). A town with heavy snow can need more, so have yours checked; the full planner looks it up. Treat the result as a starting point and confirm your design with your local building department before you build.
Describe your deck and get a blueprint, a 3D model, a priced materials list, the code check and the build steps.