Deck Material Calculator

Enter your deck's length and width, plus board coverage, to get the number of deck boards and a rough material cost.

Materials schedule

How it works

Deck area is length times width. The raw board count divides area by a single board's coverage (its length times face width). The waste-adjusted count multiplies that by (1 + waste % ÷ 100) and rounds up to a whole board.

Worked example

A 16 ft × 12 ft deck is 192 sq ft. At 16 sq ft of coverage per board with 10% waste: 192 ÷ 16 = 12 boards, × 1.10 = 13.2, rounded up to 14 boards.

Assumptions

• The deck surface is treated as a simple rectangle; add areas for L-shaped or multi-level decks.
• Board coverage is a typical figure for a given board length and face width — check your specific product.
• Framing, footings, fasteners, and railings are not included and should be estimated separately.

Reference

General construction measurement practices: International Code Council (ICC). Deck framing and railing heights are commonly governed by the IRC — check your local building department.

Related tools

• Room area calculator — the same kind of area-to-materials math for interior flooring.
• Gravel & topsoil calculator — estimate fill material under or around the deck.

Frequently asked questions