Board feet
A board foot is a standard measure of wood volume equal to 144 cubic inches, the volume of a board one inch thick, 12 inches wide and 12 inches long. A log's board-foot volume is estimated with a log rule, and the common log rules give different volumes for the same log.
A 12-inch log, measured three ways, gives three different answers
Take one 16-foot log, 12 inches in diameter. Virginia Cooperative Extension's table puts it at 95 board feet under the International 1/4-Inch rule, 80 under the Scribner rule and 64 under the Doyle rule.
The unit itself is fixed: one board foot is 144 cubic inches, a board one inch thick, 12 inches wide and 12 inches long. What changes is the log rule used to estimate how many board feet a round log holds. Extension says the Doyle, Scribner and International 1/4-Inch rules are probably the most widely used in the eastern United States, and they give different volumes for the same log.
Same log, same length, same diameter, and a spread of 31 board feet between the highest and lowest reading. On a sale measured in board feet, whichever rule is chosen is applied to every log on the load.
Extension says Doyle runs low on Virginia-size logs
Extension flags a specific problem with one of the three rules in this state.
Because nearly all logs in Virginia are below 30 inches in diameter, Extension says, for all practical purposes the Doyle rule will underestimate the actual board footage. Extension also says the buying or selling of stumpage or logs should be based on open agreement about which log rule will be used.
Which rule a particular sale uses is a term the buyer and seller settle between themselves, and the Virginia Department of Forestry says timber sales should be based on a written contract. How timber is valued covers that contract and the rest of the sale.
A board-foot total does not capture what makes hardwood valuable
Even a correctly measured board-foot total leaves out something that matters, especially with hardwood.
Why quality can count for more than volume in a hardwood stand is taken up under that term. It is one reason the volume figure from a timber cruise is a starting point for pricing, not the answer by itself.
Smaller wood is often measured another way altogether
Board feet are built around lumber. Not all wood on a tract is measured that way.
A cord is a stack of wood measuring 8 feet long, 4 feet high and 4 feet wide. Pulpwood, the smaller wood used for paper and other wood fiber products, is often measured by weight, in tons.
Trying to make sense of the board-foot volume in a timber offer?
Send what the offer says and which log rule it names. Lowell will talk through how that volume figure fits the rest of the sale, and which questions belong with a forester. No cost, no obligation.
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Questions about this term
Does the Doyle rule underestimate every log?
Extension ties its warning to log size. It says that because nearly all logs in Virginia are below 30 inches in diameter, for all practical purposes the Doyle rule will underestimate the actual board footage. The statement is about the logs a Virginia sale is likely to involve, not a claim about every log of every size.
Is board feet the measure used for pulpwood?
Often not. Extension says trees sold for pulpwood, typically smaller, lower-quality trees that will be chipped, are often measured by weight, in tons. Sawtimber, trees large enough to saw into lumber, is a different product, so a single tract can hold wood measured more than one way.
Where this page's facts come from
Every rule, office and figure above traces to one of these. Rules change; check the office before you act on one.
- Forest Landowner's Guide to the Measurement of Timber and Logs (420-085) Virginia Cooperative Extension
- Glossary: Board foot Virginia Department of Forestry
- Timber Sales (brochure, 05/2014) Virginia Department of Forestry