Log Board Foot Calculator
Compare named log scaling rules without confusing gross scale with actual lumber recovery.
- Selected rule
- Doyle
- Per log
- 144 bf
- Logs
- 1
- Gross scale
- 144 bf
Log rules are scaling conventions, not sawn yield or sale value. Measure small-end diameter inside bark and use the rule required by the buyer, contract, or agency.
Show calculation
(D − 4)² × L ÷ 16; 144 bf/log × 1 = 144 bfTransparent method and editable product assumptions. Verify current labels and project requirements.
How this calculator works
Enter the average small-end diameter inside bark and the merchantable log length. These are scaling measurements, not outside-bark butt dimensions.
The Doyle and International ¼-inch modes apply published formulas. Scribner is explicitly labeled an approximation because the official rule is table- and diagram-based.
Different rules can produce materially different scales, especially for small logs. Gross scale also excludes defect deductions and does not promise modern mill recovery.
Formula
Doyle: (D − 4)²L/16; International ¼-inch: length-dependent formula rounded to 5 bf; Scribner: stated approximationThe selected rule appears with the live result.Control example: 16 in × 16 ft log
Under the Doyle rule, board feet equal (16 − 4)² × 16 ÷ 16.
The gross Doyle scale is 144 board feet for one log.
Assumptions and limits
- Measure diameter inside bark at the small end and use the exact scaling rule, length convention, rounding and defect deductions required by the sale.
- Measurements describe one simple project geometry.
- Waste and package values are editable planning assumptions.
- It is a gross planning scale, not a timber appraisal, net defect scale, sawmill recovery forecast, grading decision, or contract measurement.
Common measuring mistakes
- Mixing nominal dimensions with actual installed coverage.
- Skipping whole-package or stock-length rounding.
- Failing to verify the page’s stated measurement and product assumptions.
- Using a planning estimate outside the limitations stated on this page.
Sources
Product-specific values remain editable. These sources support the method and stated examples; they are not a universal substitute for your supplier’s current label.
- USDA Forest Service log rules report Publishes Doyle and International ¼-inch formulas, measurement conventions and rule limitations.
- National Forest Log Scaling Handbook Defines Forest Service Scribner and International scaling practice and rounding.
Questions people ask
What does the Log Board Foot Calculator calculate?
Calculate gross log board feet using Doyle, an explicit Scribner approximation, or the International ¼-inch formula from small-end diameter and length.
How does this log board foot calculator work?
Doyle: (D − 4)²L/16; International ¼-inch: length-dependent formula rounded to 5 bf; Scribner: stated approximation
Which measurements should I enter?
Measure diameter inside bark at the small end and use the exact scaling rule, length convention, rounding and defect deductions required by the sale.
Does the estimate include every project requirement?
No. It is a gross planning scale, not a timber appraisal, net defect scale, sawmill recovery forecast, grading decision, or contract measurement.
Can I use metric measurements?
Yes. Switch to Metric above the form. The calculator converts the displayed measurements while keeping the same geometry and whole-item rounding.