What the first tool calculates
The board foot calculator computes rectangular lumber volume from the thickness, width, length and quantity you enter. Thickness and width are in inches. Length can be in feet or inches. The tool does not change entered dimensions to nominal, rough, or finished lumber sizes.
A board foot is 144 cubic inches. When length is entered in inches, dividing that length by 12 first gives the equivalent formula with a denominator of 144.
Parsing and rounding
Dimensions accept positive decimals, fractions, and mixed numbers. Examples: 0.75, 3/4, and 1 1/2. A slash is a fraction separator; a decimal point is a decimal separator. Invalid values, zero denominators, negative dimensions and non-whole quantities do not produce a usable result.
Each row is computed using JavaScript numbers, then the unrounded rows are summed. Displayed volumes use at most four decimal places; tiny positive volumes below 0.0001 BF show “< 0.0001.” The optional USD cost uses unrounded total volume and is displayed to two decimal places. This is an estimate, not financial accounting or a commercial lumber tally.
Checks included in this release
Automated numerical checks cover the 144-cubic-inch definition, equivalent inch/foot inputs, fractional and mixed-number inputs, the worked examples, separate actual and nominal inputs, quantity validation and optional pricing. These checks help detect programming mistakes. They are not independent expert certification or proof of every possible input.
Limits of the estimate
- No automatic allowance for waste, planing, defects or usable cutting yield.
- No structural capacity, load, span or connection design.
- No assumption about a supplier’s tally increments or billing convention.
- No tax, delivery, minimum purchase or processing charges in the price estimate.
Confirm purchasing dimensions and pricing with your supplier. If a result seems wrong, check the units and compare a single board manually before relying on the full list.
Revision record
November 7, 2026: initial board-foot tool, mixed-size tally, optional shared price and print view. Later tool changes will be documented here.