Last updated: September 29, 2026
Deck Planner is a deck calculator for people planning a deck of their own. Type the width, depth and height, and it draws the deck to scale with every joist, beam, post and footing, checks the joist and beam spans against published span tables, and lists the lumber, concrete, hardware and screws to buy, with quantities.
It runs free in your browser at deck-planner.app and as an app for iPhone and iPad: Deck Calculator & Planner on the App Store.
Deck Planner is made by Commonwealth Business Systems LLC, a small independent software company. We build a handful of apps and answer every support email ourselves. Deck Planner shows no ads.
Two ways, and we would rather you know both:
We may earn a commission when you buy through links on this site and app.
Deck Planner helps you plan and estimate. It is not engineering advice and it does not replace your building department, a licensed engineer or a contractor. Span and footing checks come from the American Wood Council's DCA 6 deck guide (2015 IRC) for typical conditions. Your town may use a different code edition, snow load, frost depth or soil value. Most decks need a permit. Deck Planner is not affiliated with the American Wood Council, the ICC, or any store.
Your decks stay on your device. No accounts, no ads and no analytics. The details are in the privacy policy.
Email hello@commonwealth-systems.com. A person reads every message.