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Board Foot Calculator

Calculate exact lumber board feet, a user-chosen planning allowance, and a price scenario from measured dimensions and whole-piece count.

Use this result well

Inputs that matter
Measured thickness, width, and length; whole-piece quantity; user-chosen planning allowance; and optional price per board foot
Output to expect
Per-piece and exact net board feet, entered allowance volume, planned volume, and a price scenario without supplier rounding
How it works
Thickness in inches × width in inches × length in feet ÷ 12, multiplied by whole pieces, then increased only by the entered allowance
  • Use the dimensions represented by the transaction; rough, nominal, surfaced, and finished dimensions may not be interchangeable.
  • Build the allowance from the cut list and available stock, then confirm supplier tally, rounding, minimums, species, grade, and board-by-board availability.

Choose your path

Built around the job you need to finish

Separate exact lumber volume from a visible user-chosen planning allowance without inventing a waste rate or supplier purchasing rule.

First-time woodworker

Understand board-foot volume before buying hardwood.

Enter measured dimensions and a whole-piece count, then compare net and planned volume.

Can explain the formula and knows the allowance is their own assumption.

Furniture maker

Account for a specific cut list and stock selection.

Set an allowance based on defects, grain matching, milling, and layout.

Keeps exact volume, planning allowance, and supplier tally distinct.

Small-shop estimator

Build a reproducible material-cost scenario.

Enter a price per board foot and review the unrounded volume and cost.

Confirms supplier rules before turning the scenario into an order or quote.

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Reference & details

How it works

Standard board foot formula

One board foot is a volume equal to 12 inches by 12 inches by 1 inch. Length is entered in feet, so the formula divides by 12.

board feet = thickness in x width in x length ft / 12

User-entered allowance

The calculator reports net volume first, then adds only the percentage you enter. It does not prescribe a waste rate or round to a supplier tally because cut lists, stock quality, species, grain matching, and sales practices vary.

Cost scenario boundary

Price is multiplied by the planned board-foot volume without package, minimum-charge, or supplier-tally rounding. Treat it as a comparison scenario and reconcile the actual stock list and invoice method separately.

Updated: August 2026

Example Scenarios

Measure the transaction dimensions, calculate exact volume, then choose an allowance from the cut list, required grain selection, and available stock.

Combine board feet and price per board foot to estimate material cost before labor.

Common Mistakes to Avoid

Using nominal dimensions

Measure actual thickness and width after milling or use supplier listed dimensions.

Treating a generic waste percentage as a purchase order

Build the allowance from the actual cut list, defects, grain requirements, milling losses, minimum charges, and the supplier's tally and rounding rules.

FAQ

One board foot is 144 cubic inches, equivalent to a board 1 inch thick, 12 inches wide, and 12 inches long.

Use the dimensions you are paying for when estimating purchase cost. Use finished dimensions when checking project yield.

There is no universal percentage. Derive it from your cutting layout, defects and end checks, grain matching, milling state, experience, and the boards actually available. The calculator keeps that assumption visible instead of selecting it for you.

Not necessarily. Supplier tally methods, minimums, thickness conventions, rounding, and board-by-board stock can differ. Confirm the exact purchasing method before ordering.

About Board Foot Calculator

Separate exact lumber volume from a planning allowance you control. Enter the dimensions used for the transaction, a whole-piece count, your own allowance, and an optional price per board foot.