How to Buy Hardwood by the Board Foot: 4/4 Nominal Explained

Hardwood is sold by volume, not by the piece, and the unit of volume is the board foot. Buyers who come from retail lumber, where everything is a fixed size at a fixed price, often find the system confusing at first. It is actually simple once the three ideas underneath it are clear: what a board foot is, what nominal thickness means, and who counts the wood. This article covers all three, plus a note on resale certificates for Illinois shops.

Our Long Premium teak is listed per board foot on 4/4 nominal, which is the basis described below.

What a board foot is

A board foot is 144 cubic inches of wood: one inch thick, twelve inches wide, twelve inches long. Any board with the same volume is one board foot regardless of its shape.

The formula in inches is thickness times width times length, divided by 144. If you prefer to keep length in feet, the formula is thickness in inches times width in inches times length in feet, divided by 12. Both give the same answer.

Worked examples at 4/4

• A board 6 inches wide and 8 feet long: 1 × 6 × 8 ÷ 12 = 4 board feet.
• A board 4 inches wide and 6 feet long: 1 × 4 × 6 ÷ 12 = 2 board feet.
• A board 5 inches wide and 3 feet long: 1 × 5 × 3 ÷ 12 = 1.25 board feet.

Add the board feet of every board in the stack and you have the tally. Multiply the tally by the price per board foot and you have the invoice.

What 4/4 nominal means

Hardwood thickness is expressed in quarters of an inch. 4/4, spoken as four-quarter, means one inch. The word nominal means the thickness used for billing, which is not necessarily the thickness you measure with calipers. Lumber is sawn a full inch; once it is planed to final dimension, the finished board is thinner. The trade convention is that the board is still billed as 4/4.

Our teak is dimensioned stock with actual thicknesses from three-quarters of an inch to one inch, and it is sold on 4/4 nominal. That is the standard convention and it is the reason a per-board-foot price from us can be compared directly to a per-board-foot price from any other hardwood supplier quoting on the same basis. When you compare quotes, confirm the nominal thickness first. A price on 4/4 and a price on 5/4 are not the same price.

Why the tally at loading governs

Every board is a different width and length, so the total board footage of a lot is not known precisely until each board is measured. In the trade, the count and measurement taken at the moment the wood is loaded onto the buyer's vehicle or the carrier is the tally that governs the sale. Estimates given before that point are estimates.

This convention protects both parties. The seller is paid for what actually left the dock. The buyer pays for what actually arrived, not a figure from a listing. At our Lincolnwood dock, will-call pickup is free by appointment, and the buyer inspects and tallies at loading. You measure with us, you agree on the number, and that number is the invoice. Delivery and freight are always quoted separately from the lumber, so the board-foot price stays clean.

How we organize stock to make buying easier

Our Ecuadorian teak is heartwood-dominant on both faces, in trade widths from two to seven inches and lengths from one to eight feet. Rather than mix everything in one pile, we hold it in four length classes:

• Long Premium, 7 to 8 feet, for furniture rails, long panels, and casework.
• Mid-Length, 5 to 6 feet, for doors, seating, and mid-size parts.
• Short Stock, 1 to 4 feet, for cutting boards, boxes, knife scales, and turning; ships by parcel nationwide.
• Face-Frame and Edge-Banding, 7 to 8 feet narrow, for frames and edge treatments.

Each class is priced per board foot on 4/4 nominal. Provenance is the same across all of them: Legally imported, plantation-grown Ecuadorian teak — CBP-entered, duty-paid. We hold roughly 10,000 saleable board feet across the four classes.

Resale certificates for Illinois shops

If your shop buys lumber to build products for sale, the lumber purchase is generally for resale and may be exempt from Illinois sales tax at the time of purchase. The mechanism is Form CRT-61, Certificate of Resale, issued by the Illinois Department of Revenue. The buyer completes it with the business name, address, and Illinois account or registration number, describes the property being purchased for resale, signs it, and gives it to the seller. The seller keeps it on file to document why tax was not collected.

A few practical points:

• The certificate covers purchases for resale, including materials that become part of a product you sell. It does not cover shop supplies or equipment you keep.
• Provide the certificate before the first tax-exempt purchase, not after the invoice is written.
• A blanket certificate can cover ongoing purchases from the same seller; ask whether the seller accepts one.
• Out-of-state buyers should consult their own state's resale certificate rules; Illinois accepts certain out-of-state certificates in specific circumstances, which is a question for your accountant.

Trade buyers can send a completed CRT-61 when registering through our trade page, and we will keep it on file for future orders.

Next step

Start with the Long Premium teak listing to see per-board-foot pricing on the 4/4 basis, or browse the full Ecuadorian teak lumber collection. To set an appointment at the Lincolnwood dock, contact Norman at (773) 584-7334 or info@platinumluxuryteak.com.