Board Foot Calculator for Lumber

Board Feet: The Standard Unit of Lumber

A board foot (BF) is a unit of lumber volume equal to a piece 12 inches long × 12 inches wide × 1 inch thick (144 cubic inches). It is the universal measurement used by lumber yards and hardwood suppliers to price wood regardless of dimension.

The Board Foot Formula

Nominal vs. Actual Dimensions

Lumber is sold by nominal dimensions (e.g., a "2×4"), but actual dimensions are smaller after drying and surfacing. A nominal 2×4 measures approximately 1.5" × 3.5" (actual). Always use actual dimensions for structural calculations, but board foot pricing typically uses nominal dimensions.