Lumber basics

Board Feet

Board feet measure lumber volume. One board foot equals 144 cubic inches of wood.

Lumber sellers often use board feet to price hardwood, slabs, and other stock where boards vary in width, length, or thickness. The measurement describes volume, so it accounts for all three dimensions instead of just the face of a board.

Calculate board feet for a lumber list with quantities, unit choices, and an optional cost total.

What one board foot looks like

A piece of wood that is 1 inch thick, 12 inches wide, and 12 inches long is one board foot. Other combinations can equal the same volume: a 2 inch × 6 inch × 12 inch board and a 1 inch × 6 inch × 24 inch board are also one board foot.

Board feet vs. square feet

Square feet measure area. Board feet measure volume. A square-foot calculation uses length and width; a board-foot calculation also includes thickness. Two boards with the same face area can have different board-foot totals when one is thicker.

When board feet are useful

• Comparing hardwood prices quoted per board foot.
• Estimating the total volume in a cut list with mixed board sizes.
• Checking a supplier's tally before ordering lumber.
• Turning a board-foot price into a material-only cost estimate.

How board feet are calculated

For dimensions in inches and feet: thickness (in) × width (in) × length (ft) ÷ 12. Multiply that result by quantity for matching boards. Keep each board size on a separate row, then add the row totals.

For example, one 1 inch × 10 inch × 8 foot board contains 6.667 board feet. Four of those boards contain 26.667 board feet.

Before using a board-foot quote

Confirm whether the quote uses nominal or actual dimensions, whether the wood is surfaced, and how the seller rounds its tally. Board feet describe volume accurately, but a final invoice may also reflect the supplier's grading, milling, and rounding practices.

Board feet questions