Formula
Rows = round up (coverage width + gap) ÷ (board width + gap). Rows × board run length gives linear footage.
Deck Board Calculator
Estimate deck-board rows, linear footage, and a whole-board planning quantity from the direction and spacing.
How this deck board estimate works
Board orientation changes both the number of rows and the length of every run. This planner makes that choice explicit before adding a cut allowance.
Worked example
For a 20 × 15 ft deck with boards running along the length, rows are counted across the 15 ft dimension. Add the selected allowance, then compare the result with a stock board length.
Before you buy
Use the whole-board count as a starting point, then lay out joints and cuts before buying. Long boards can reduce joints but may increase handling and waste.
Assumptions
Defaults are starting points. Replace coverage, density, package yield, spacing, and allowance values with the product or plan you are actually using.
Limitations
The estimate does not create a cut list or account for picture framing, borders, angles, stair treads, joist layout, defects, or local lumber availability.