Lumber Calculator

Lumber is commonly estimated in board feet, a volume measure used for rough and hardwood boards. One board foot represents a piece twelve inches wide, one inch thick, and one foot long, which equals 144 cubic inches. The calculator multiplies thickness in inches by width in inches by length in feet, divides by twelve, and multiplies by the number of boards. This makes it easy to compare orders containing boards with the same dimensions. Board-foot calculations normally use nominal dimensions when a seller prices rough lumber that way, but construction lumber is often dressed smaller than its nominal name. A nominal two-by-four may actually measure about 1.5 by 3.5 inches. Use the dimensions required by your estimate: nominal dimensions for a quote expressed in nominal board feet, or measured dimensions when you need actual volume and weight. Mixing the two conventions can overstate or understate material requirements. Cubic volume is derived by dividing board feet by twelve. Estimated weight then multiplies cubic feet by density in pounds per cubic foot. Density depends on species and moisture content, so select a value appropriate for the supplied lumber. Green oak, kiln-dried pine, and pressure-treated framing can differ substantially. Published density tables are useful starting points, while supplier data or direct weighing gives better results for transport and structural handling. The optional cost field multiplies total board feet by a price per board foot. It does not add sales tax, delivery, milling, waste, fasteners, or labor. Retail dimensional lumber is frequently sold by the piece instead, in which case multiply the supplier's piece price by quantity outside this board-foot pricing field. Always confirm whether a quote uses nominal or net tally and whether length premiums apply. Projects should include waste for cuts, defects, grain matching, and mistakes. Straight framing layouts may need a modest allowance, while furniture, flooring, or appearance work can require more because color and grain selection reduce usable yield. The calculator reports the geometric order as entered, leaving you free to increase quantity according to the project. Review span tables, grades, treatment requirements, and local codes separately because volume alone does not establish whether a board is structurally suitable.