SawTallyOpen the appDoyle vs. Scribner vs. International log rule
Which rule to quote from · last checked September 25, 2026.
All three are ways to estimate the board feet of lumber inside a log from its small-end diameter and length. They disagree on purpose — and the gap is biggest on small logs, where Doyle can read less than half of the International rule. Quote from the wrong one and you either lose money or lose the job.
The three rules
| Rule | How it behaves | Where it's common |
|---|---|---|
| Doyle | Subtracts 4″ for waste then squares — under-scales small logs, over-scales very large ones. | Eastern US |
| Scribner Decimal C | A diagram rule, rounded to the nearest 10 bd ft. Middle of the road. | Western US |
| International 1/4-inch | Accounts for taper and 1/4″ kerf; most accurate, closest to real sawn yield. | Research, most accurate |
See the gap yourself
Run a 10-inch, 12-foot log through the three rules and Doyle reads far lower than International. That's not an error — it's the rule's built-in waste allowance. On big, clean logs the rules move closer together.
Compare all three on your log →
Which one to quote from
There's no "right" rule — there's the rule your buyer expects. If you sell logs to a mill, use their rule. If you saw for a landowner, Doyle is common in the East, Scribner in the West. Two things matter more than which rule:
- Agree on the rule before you quote. A customer expecting Doyle numbers will balk at International.
- Be consistent. Whatever you quote from, tally the finished lumber the same way so your invoice matches your promise.
Quote and tally in one place
SawTally scales the log by all three rules for your quote, then keeps a running board-foot tally of what you actually cut — so the invoice reflects real lumber, not a guess. Free to start.
Log rules are estimates from published forestry formulas and differ from actual sawn yield. Confirm the rule and figures your buyer uses. Not financial advice.