Log board-foot estimator

Measure diameter at the small end inside the bark and enter the nominal scaling length. Choose the log rule you intend to use. Diameter must be 4–120 inches, Doyle length 4–40 feet, and quantity 1–10,000 whole logs.

Doyle: BF = (D − 4)² × L / 16

The International quarter-inch method uses the length-specific equations from USDA SRS-251, Appendix B, and rounds each log to the nearest five board feet. Available nominal lengths are 4, 8, 12, 16 and 20 feet.

For a 16-inch small-end diameter and 16-foot length, Doyle gives 144 board feet. The International equation gives 180.546 before rounding and 180 board feet after rounding.

Source: USDA Forest Service SRS-251, May 2020, Appendix B

The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.

Log rule

Doyle

Small-end diameter inside bark

16 in

Nominal log length

16 ft

Identical logs

1

Primary result: Estimated board feet: 144 bd ft.

• Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
• Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
• When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

These are log-rule yield estimates, not the geometric volume of a solid cylinder or a guaranteed lumber tally. Actual recovery depends on defects, taper, saw kerf, edging and milling practice. Use the rule and scaling conventions required for your transaction.