Lumber Tally field notes

Methodology

How this calculator computes board feet and cost: the formula, unit handling, and what it deliberately does not do.

Board feet for each row is computed as (thickness × width × length) ÷ 144, with every dimension first converted to inches. Quantity multiplies the per-board result. Cost, where a price per board foot is given, is board feet × price. We sum unrounded results, then display volume to at most four decimal places and USD cost to two. Browser floating-point arithmetic has finite precision; the displayed numbers are not exact measurements.

Input handling

Thickness, width, and length each carry their own unit — inches, feet, millimeters, centimeters, or meters — so a board measured in mixed units can be entered as measured. Values accept plain decimals (1.5), simple fractions (3/4), and mixed fractions (1 1/2).

What "thickness" means here

The calculator uses the number you type. For physical volume, enter measured dimensions. For a buying estimate, ask your supplier which dimensions they bill; nominal rough thickness is a common convention, but not a guarantee about every invoice. See lumber thickness and the quarter system and rough vs. finished lumber.

Invalid and unpriced rows

A row with a missing or unusable measurement is marked invalid, excluded from the board-foot and cost totals, and counted separately so the total row count and the tallied row count never silently disagree. A row with no price entered is tallied for board feet but excluded from the cost subtotal and counted as unpriced — it is not treated as free.

What this is not

This is a measuring and arithmetic tool, not a pricing service, a grading service, or a log-scaling estimator. It does not estimate lumber yield from a log (that is what log rules such as Doyle or Scribner are for), and it does not verify your measurements against an actual board. For a purchase that matters, confirm the final tally and price against your supplier's own invoice.

Back to the calculator.