Decking Calculator

How Decking Calculator Works

Deck area is divided by the width of a single board to get the total linear footage of boards needed side by side, with a waste allowance added for end cuts and fitting.

Who Uses Decking Calculator and Why

• Estimating linear footage of decking boards needed for a new deck build.
• Comparing material needs between two board widths for the same deck footprint.
• Converting a linear footage total into an actual board count once you've picked a specific board length.

Mistakes to Avoid

• Confusing linear footage with a board count — the calculator gives total linear feet of decking needed side by side, which still needs dividing by your chosen board's actual length to get a purchasable board count.
• Leaving board width at the 5.5-inch default when your actual decking product is a different width — common deck boards vary (5.5 inch is typical for standard 6-inch nominal boards, but composite and other profiles differ).
• Not adding waste for end cuts and staggered seams, especially on a deck with an irregular shape or multiple courses that need offsetting for structural reasons.

Tips for Best Results

• Once you have the linear footage total, divide by your specific board's actual length (accounting for the gap between boards, if the tool doesn't already) to get a real board count for ordering.
• Increase waste above the 10% default for a deck with angled cuts, picture-frame borders, or diagonal board layout.

Fixing Common Problems

I don't know how to turn the linear footage result into a number of boards to buy. — Divide the total linear footage by the length of the specific board you plan to use (e.g., a 12-foot board) and round up — the calculator intentionally reports linear footage since board lengths vary by what's available.

Terms Explained

Linear footage: A total length measurement independent of individual piece length — used here because deck boards come in varying lengths.