Deck material

Decking Boards Calculator

Estimate deck board count using board width, gap and board length.

Board layout assumptions

This simple model assumes boards run along the deck length. Angled decking, borders, breaker boards and stair treads require a more detailed takeoff.

Example

For a 16 ft by 12 ft deck using 5.5 inch boards with 0.25 inch gaps, each row covers 5.75 inches. About 26 rows are needed before waste and layout adjustments.

Common mistakes

Remember to include board gaps, trim, breaker boards and waste from cuts. Board direction also changes the count.

Limitations

This calculator estimates board count only. It does not cover framing, fasteners, stairs, railing, permits or structural design.

Last reviewed: 2026-05-17

Before relying on this result

Use this calculator together with the formula, assumptions, limitations and examples on the page. If the topic involves health, tax, lending, investment, legal, safety or current-rate decisions, treat the number as an estimate and check the relevant primary source or professional guidance.

Calculator metadata last reviewed: 2026-05-14.