Which rule should I use?
Doyle — ((D − 4) ÷ 4)² × L — is what most sawmills and log buyers quote. It undercounts small logs badly (the 4″ slab allowance is huge on a 10″ log), which is why sellers prefer other scales.
International 1/4″ tracks actual sawmill recovery best. It scales the log in 4-foot sections with 1/2″ of taper per section and allows a 1/4″ kerf.
Scribner predates both, drawn from diagrams of 1″ boards inside a cylinder. Still common in the western U.S. (shown here as its formula estimate).
| Small end | Doyle, 10 ft | Int'l 1/4″, 10 ft |
|---|---|---|
| 10″ | 22.5 | 37 |
| 14″ | 62.5 | 80 |
| 18″ | 122.5 | 139 |
| 22″ | 202.5 | 214 |
Values computed with the formulas this tool uses; printed mill tables round differently by a few board feet.
Sawing boards from the estimate? Price the yield in the planner.