Deck Calculator
Calculate decking materials โ boards, joists, screws, and support posts needed for your deck. Enter dimensions and board specifications for a complete material list.
๐ชต Deck Calculator
Results
Deck Area192.00 sq ft
Deck Boards35 boards
Total Linear Feet420.00 lin ft
Joists10 joists
Support Posts6 posts
Deck Screws700 screws
Est. Board Cost$525.00
๐ก How to Calculate Deck Materials
Deck board quantity depends on the board width and deck dimensions. Standard 5/4ร6 deck boards have a 5.5-inch face width. Divide the deck width by the board face width to get the number of boards, then each board runs the full deck length (or is spliced over a joist for longer spans).
Joists are typically spaced 16 inches on center (12 inches for composite decking). Support posts go under beams, spaced no more than 6โ8 feet apart in both directions. Plan for 2 deck screws per board per joist crossing โ that adds up quickly on a large deck.
A 12ร16 ft deck using 5.5" boards = 35 boards ร 12 ft each. With 16" OC joists = 10 joists. Support posts: 2ร3 = 6 posts. Deck screws: 35 ร 10 ร 2 = 700 screws.