Deck Board Material Calculator

Calculate board rows, linear feet, and boards needed for a deck surface.

⏱ Updated: 18 Sep 2026

Calculator

Free deck board material calculator: find rows, linear feet, and boards needed for a deck surface.

Boards Needed
Board Rows
Linear Feet (with waste)

Assumes boards run the full deck length, across the deck width, with a standard 3/16" gap for drainage and expansion. Boards that run the other direction, or a picture-frame border, will change the actual cut list.

Enter deck dimensions and board width to calculate board rows, linear feet, and boards needed.

How to Use the Deck Board Material Calculator

Enter the deck's length and width, the actual board width and gap you're installing, and the board length your supplier stocks. The calculator assumes boards run the full deck length in rows spaced across the width.

Decking is sold by nominal size, and a "5/4x6" board isn't actually 6 inches wide, so the width that matters here is the board's actual, measured face width, not the label printed on it. Most composite and pressure-treated decking runs about 5.5 inches actual for a nominal 6-inch board.

Rows, Then Linear Feet

rows = ceil((deck width in inches) ÷ (board width + gap))
linear feet = rows × deck length × (1 + waste%)
boards needed = ceil(linear feet ÷ board length)

Each row runs the entire deck length, so the total linear footage needed is the row count multiplied by that length, then padded for waste and divided by whatever length the boards actually come in.

This Assumes a Simple Layout

A picture-frame border, a diagonal or herringbone pattern, or boards running the deck's width instead of its length all change this math in ways a single formula can't capture cleanly. Treat this as the estimate for the common case, straight boards running the long dimension, and adjust by hand for anything more elaborate.