Deck Calculator

How much material do I need for a deck?

ft
ft
Joist spacing
Decking length

Order this much 5/4 × 6 decking

2916 ft boards

A planning list with 10% extra on boards. Joist size, footings and ledger attachment are code items, so confirm against local code or use the joist and footing tools.

Decking runs the long way16 ft12 ftJoists at 16 in on center
Deck area192 sq ft
Joists13 at 12 ft
Rim board56 ft
Deck screws676

Start with your deck size and get boards, joists, rim and screws on one list. Use the deck joist and footing pages for the code-driven sizing.

How it works

Boards are the rows across the depth multiplied by the run with 10% added. Joists are the deck length ÷ spacing, plus one.

Before you order

  • Plan board lengths so butt joints land on joists and stagger across the deck.
  • Double up joists where boards meet at a break line.
  • Pull a permit first, since inspectors check the ledger and footings as well as the surface.

Common questions

How many boards does a 12 × 16 deck need?

About 28 rows of 16 foot boards at 5.5 inch width, so roughly 30 with waste.

Do I need a permit for a deck?

Most areas require one for attached or raised decks. Ask your building department.