A useful lumber tally begins before any multiplication. Gather the dimensions, decide what those dimensions represent, and keep each board group on its own row. That preparation makes the total explainable when stock sizes, quantities, or a quote change. LumberCalc performs the volume arithmetic, but the user remains responsible for selecting the source measurements and confirming what the supplier will bill.

Declare the basis once

Label the tally as actual measurements, nominal references, or supplier-billed dimensions. Actual means values physically measured on the stock. Nominal means trade names or reference sizes entered literally. Supplier-billed means the dimensions printed on the quote or invoice. The label does not convert anything. If a board is called 2 × 4 but measures differently, choose which scenario you are checking and enter that scenario’s values instead of mixing both in one row.

Group only genuinely equal boards

Create one row for boards sharing thickness, width, length, and basis, then use quantity for repeated pieces. Keep different lengths or measurements separate even when the species and label match. An optional short label such as “walnut rails” helps comparison, but it does not influence the formula. Check units carefully: imperial rows use inches for thickness and width and feet for length; metric rows use millimetres and metres. Record waste or spare pieces as deliberate extra rows, not as a hidden percentage.

Reconcile the total with the source

For imperial inputs, each row becomes cubic inches and board feet are cubic inches divided by exactly 144. Totals are aggregated before display rounding. Compare row by row rather than only matching the grand total: one wrong quantity can be hidden by another difference. If the supplier applies rounding, minimum billing, rough-thickness conventions, or grading rules, ask for those rules and reproduce the billed dimensions explicitly. LumberCalc does not certify a purchase, optimize cuts, or determine whether the selected material is structurally suitable.