What this calculator measures
A log rule estimates the amount of one-inch lumber that may be sawn from a round log. The rules do not measure the same thing as cubic volume, and the same log can produce different board-foot estimates under different rules.
How to measure
Measure the diameter at the small end of the log, inside the bark. Use nominal log length. For an oval log end, average two perpendicular diameter measurements.
Do not use this as a timber appraisal. Defect, sweep, taper, grade, species, local scaling practice, utilization standards, and the buyer's specified log rule all affect merchantable value.
Calculation notes
Doyle is calculated from the standard formula. Scribner is shown using a common Decimal C equation approximation. International ¼-inch values use the published common-length table for whole-inch diameters from 8–30 inches.
Reference methods: University of Florida IFAS timber inventory guide and Penn State Extension timber valuation guide.