Free · no sign-up · prints clean

Board Foot Calculator

Build your lumber tally like you're standing at the yard: add each board, pick a 4/4–16/4 thickness or type inches, and get total board feet plus estimated cost. The board foot formula is BF = thickness″ × width″ × length′ ÷ 12, figured on nominal dimensions.

Your boards
ThicknessWidth ″Length ′QtySpecies / $ per bfbd ft

Quick answers — dimensional lumber

How board feet work

A board foot is the standard volume unit for hardwood lumber in North America: one board foot is a piece 1 inch thick, 12 inches wide and 12 inches long — 144 cubic inches of wood. Sawmills, hardwood dealers and lumber yards all price rough lumber by the board foot, so knowing your project's total is the difference between a confident order and an awkward second trip.

The formula this calculator uses is the same one the yard uses: thickness (inches) × width (inches) × length (feet) ÷ 12. If your length is in inches too, divide by 144 instead. Two conventions matter:

Enter each board on its own line — the tally slip on the right adds everything up, applies your $/bf prices, and prints as a clean cut list you can take to the yard. Your boards stay in your browser (nothing is uploaded), so the list is still here when you come back.

Worked example

Say a coffee-table build needs two 8/4 walnut boards 7″ × 8′, and eight 4/4 maple boards 6″ × 10′. The walnut is 2 × 7 × 8 ÷ 12 × 2 = 18.67 bf; the maple is 1 × 6 × 10 ÷ 12 × 8 = 40 bf. At $11.50/bf and $7.25/bf you're looking at 58.67 bf and roughly $505 — before waste. Most woodworkers add 15–30% for defects, grain matching and mistakes; buy the extra board now and thank yourself later.

Buying tips from the tally

FAQ

How do you calculate board feet?

Multiply thickness in inches × width in inches × length in feet, then divide by 12. Example: a 2×6 that's 10′ long = 2 × 6 × 10 ÷ 12 = 10 board feet exactly.

Board feet vs linear feet — what's the difference?

A linear (lineal) foot only measures length along the board; a board foot measures volume. Convert between them with the BF ↔ LF converter — you need the board's width and thickness to do it.

Is plywood measured in board feet?

No — sheet goods are sold by the sheet or square foot. Board feet are for solid lumber. For coverage math at a given thickness see BF ↔ square feet.

How much should I add for waste?

15% for straightforward paint-grade work; 25–30% for furniture where you'll cut around knots and match grain. Rough lumber surprises you — always in the wrong direction.

More lumber math