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Deck Board Calculator

Estimate deck boards and lineal feet from deck width, board width, gap, length, and waste.

Reviewed
2026-09-05
Units
US + metric

Calculated result / live

19 deck boards

Order 19 boards cut to 10.00 ft, then lay out the field to confirm the last board.

7.25 in actual board width with a 0.125 in gap, 10% waste. Boards run along the 10.00 ft direction.

Input panel

Project measurements

Secondary quantities
Boards across17
Base lineal feet170.0
Ordered lineal feet187.0
Ordered boards19

Calculation trace

Formula with your numbers

⌈10.00 ft × 12 ÷ (7.25 + 0.125) in⌉ = 17 boards across; × 10.00 ft = 170.0 linear ft

19 deck boards
01

What this deck board calculator calculates

A 10 ft wide deck with 5.5 in actual boards and a 1/8 in gap needs 22 boards across before waste.

Formula

Ceiling(deck width × 12 ÷ (actual board width + gap)) = boards across; boards × run length = lineal feet.

Worked example

For a 10 × 12 ft deck, 22 boards across × 12 ft = 264 lineal ft. Ten percent waste is 290.4 lineal ft, or 25 boards rounded by count.

Ordering decision

Picture framing, breaker boards, stairs, fascia, and blocking are separate from the field-board quantity.

The page cites the applicable Uzi Tools reference table beside the calculator. Product labels, current editions, local code, and a licensed professional govern structural, electrical, and life-safety work.

02

How to use it

  1. Enter the measured dimensions and keep the displayed units beside each field.
  2. Review the deck boards across a field result and the substituted formula before ordering.
  3. Adjust waste for the layout, cut pattern, product package, and site conditions.
  4. Copy or print the material list, then verify the cited product data and local requirements.
03

Deck boards across a field

This deck board calculator counts boards across the deck width after including the selected gap, then reports lineal feet along the run and a cut allowance.

04

Limits and professional review

Measurements, product yield, waste, moisture, and site conditions can change the order quantity. Local code and a licensed professional govern structural and electrical work.

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Data sources

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Questions specific to this estimate