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Board Foot Calculator — Lumber Volume & Cost

Calculate board feet per piece and total lumber volume with quantity, waste allowance, and price.

Quick answer

One board foot is a lumber volume of 144 cubic inches. Multiply thickness × width × length in inches, divide by 144, then multiply by quantity and add cutting waste.

Your planning estimate46 board feet

4 BF per board · 80 total linear ft.

Measured need40 BF net lumber volumeBuy / plan46 BF after 15% allowance
Formula: thickness (in) × width (in) × length (ft) ÷ 12 × quantity
Shopping list
  • Lumber46 board feet

Ask the lumberyard whether it tallies nominal, rough, or surfaced dimensions and how it rounds. Board feet measure volume, not linear or square coverage.

Use it well

Step by step

  1. 1

    Enter actual or quoted thickness and width carefully; nominal lumber dimensions can differ from dressed dimensions.

  2. 2

    Calculate board feet per piece, multiply by quantity, and add waste for defects and cut layout.

  3. 3

    Apply the supplier’s price basis—per board foot or per piece—and verify tally rules before purchase.

Worked example

Check the estimate before you buy

Calculate board-foot lumber volume per piece and for a full batch, then add milling or cut allowance and optional price per board foot.

Example

One board measuring 1 in thick × 6 in wide × 8 ft long contains 4 board feet. Ten identical boards contain 40 board feet before a 15% allowance, or 46 board feet to plan.

How the calculation works

Multiply thickness in inches by width in inches by length in feet, divide by 12, then multiply by quantity. Allowance and price are applied to the batch total.

Planning checklist

Before you place the order

  • Confirm whether the lumberyard tallies nominal, rough, or surfaced dimensions.
  • Use the yard's actual price per board foot rather than a species average.
  • Choose an allowance that reflects defects, grain selection, milling, and your cut list.
Common questions

Board Foot Calculator — Lumber Volume & Cost FAQ

What is one board foot?

One board foot is 144 cubic inches of wood—the volume of a board 1 inch thick, 12 inches wide, and 12 inches long.

Is a board foot the same as a linear foot?

No. A board foot measures volume, while a linear foot measures length only.

Should I enter nominal or actual dimensions?

Follow the lumberyard's tally convention. Rough hardwood and dimensional softwood may be priced differently.

How is lumber cost calculated?

Multiply the board feet you plan to buy by the supplier's price per board foot.

Source & method

Reference: Virginia Department of Forestry board-foot definition. Results are practical estimates; complete labels, package directions, product specifications, and qualified professional advice take priority.