Board Feet vs Linear Feet vs Square Feet

The distinction in board feet vs linear feet vs square feet is the measurement being sold. Linear feet measure length. Square feet measure area. Board feet measure wood volume, expressed in units of 144 cubic inches. A quote of “$6 per foot” is incomplete until the seller identifies which foot.

One board, three correct measurements

Take a rectangular board whose stated measurement basis is 2 inches thick, 9 inches wide and 8 feet long. These are the dimensions for this example, not a nominal-to-finished conversion.

Four identical boards total 32 linear feet, 24 ft² of broad-face area and 48 board feet on this basis. They are four pieces, not 48 pieces. None of those totals tells you which cuts can be obtained without checking each board's length and usable width.

Board feet vs linear feet: you need the cross-section

Eight linear feet of a thin strip and eight linear feet of a thick plank have equal length, not equal wood volume. To turn a linear-foot quote into a board-foot quote, you also need the thickness and width used for billing.

For the example board, suppose supplier A charges a hypothetical $6 per BF: the piece costs $72. Supplier B offers the same size and specification at $8.50 per LF: the piece costs $68. Comparing the bare numbers 6 and 8.50 would select the higher-priced piece.

This comparison works only if the wood, grade, condition, usable dimensions and included services are comparable. Surfacing or delivery charges can change the final bill. The prices are arithmetic examples, not market rates.

Board feet vs square feet: thickness changes the answer

The example board has 6 ft² of face area at 2 inches thick, which is 12 BF. At 1 inch thick, that same rectangular face would represent 6 BF. At ¾ inch thick, its geometric volume would be 4.5 BF. Equal face area does not imply equal board footage.

Face area is also not always installed coverage. Tongues, grooves and overlaps can reduce the exposed width. For decking, gaps form part of the layout but are not wood surface area. Use the product's installed dimensions and a layout when estimating coverage; do not turn a total BF figure into a finished floor or deck area without those details.

Ask which dimensions the seller uses

A physical-volume calculation can use measured dimensions. A commercial tally can use the seller's stated convention, including nominal thickness or a specified rough-lumber basis. Those numbers may differ even when everyone is describing the same piece.

For example, Woodworkers Source explains that its board-foot measurement uses a hardwood thickness name such as 4/4 as 1 inch even when the surfaced piece measures less. That is a specific sales practice to understand, not a rule to impose on every supplier or product.

• Is the price per piece, LF, ft², BF or a larger tally unit?
• Which thickness, width and length go into the billed quantity?
• Is the stock rough, surfaced or sold to a finished size?
• Are machining, selection and delivery charged separately?

Write the answers beside the quote. Then compare the total for the same usable material. A unit conversion cannot recover wood removed by surfacing, make a narrow board wider or turn offcuts into the lengths your project needs.

Once the measurement basis is clear, use the board foot calculator to total your board sizes and apply a quoted price.

Measurement references

Penn State Extension defines a board foot as 144 cubic inches. The American Hardwood Export Council guide explains hardwood measurement and tally conventions. Woodworkers Source's measurement guide illustrates a retailer's thickness basis. Our board and quote examples are independent calculations.