What diameter should I enter?

Enter the representative average small-end diameter inside bark (DIB) of the 16-foot logs, not the tree diameter at breast height. Upper logs taper, so using full DBH for every section can substantially overestimate stand volume.

What is a 16-foot log section?

Sawlogs are commonly bucked into 16-foot lengths (sometimes 8 or 12 feet). Merchantable height divided by 16 gives the number of log sections. Enter 1 for trees with only a single log, 2 for two logs, etc.

Which log rule gives the most board feet?

The International 1/4" rule is generally the most accurate and produces the highest estimates. Scribner is intermediate. Doyle consistently under-estimates small-diameter logs (under 16") and over-estimates large ones (over 28"), so it often produces the lowest value for typical stands.

Are these estimates exact?

No — log rules are yield formulas, not measurements. Actual recoverable lumber depends on log taper, sweep, crook, rot, and mill efficiency. These estimates are a planning baseline, not a guarantee.

What species or region is this for?

Doyle, Scribner, and International 1/4" rules use small-end log diameter and log length. They are used across North America regardless of species. Always confirm which rule and scaling practice are standard in your region or timber contract.

Can I use metric inputs?

This calculator uses inches and feet, which are the standard units for these log rules. To convert, multiply centimeters by 0.394 for inches and meters by 3.281 for feet.

Timber Yield Calculator

Enter average small-end log diameter, 16-foot logs per tree, and stand count to estimate board-feet yield under three common log rules.

Stand Parameters

Average Log DIB (inches) — small-end diameter inside bark

16-ft Log Sections per Tree — merchantable height ÷ 16

Number of Trees in Stand

Log Rules to Display

Doyle Scribner International 1/4"

Enter stand parameters and click Calculate Yield to see results.

Board-Foot Yield by Log Rule

Per-log, per-tree, and stand totals

Log Rule	BF / Log	BF / Tree	Stand Total (BF)

Doyle: (D − 4)² × L / 16 — Simple; under-estimates small logs, over-estimates large ones.

Scribner: 0.79D² − 2D − 4, per 16-ft log — Tabular rule widely used in the US Pacific Northwest.

International 1/4": Formula accounting for a 1/4" saw kerf and log taper — most accurate of the three.

BF = board feet. All estimates assume standard 16-ft log sections with 1/2" taper per 4-ft length (International rule).

Summary

This timber yield calculator estimates the total board-foot volume of a stand using three industry-standard log rules: Doyle, Scribner, and International 1/4". Enter a representative average small-end diameter inside bark (DIB) for the 16-foot logs, the number of logs per tree, and total tree count to get per-tree and stand-level estimates. Using log DIB instead of tree DBH avoids treating upper logs as if they had the full breast-height diameter.

How it works

Enter the representative average small-end diameter inside bark (DIB) of the 16-foot logs.
Set the number of 16-foot log sections (bolts) per tree — this is the merchantable height divided by 16.
Enter the total number of trees in the stand.
Select which log rules to display (Doyle, Scribner, and/or International 1/4").
The calculator applies each selected formula per log section, multiplies by the number of logs and trees, and shows per-tree and total stand board-feet.
Use the results table to compare rule estimates and plan your timber sale or harvest.

Use cases

Estimate board-foot volume before listing timber for sale.
Compare Doyle, Scribner, and International 1/4" yields to choose the most favorable rule for negotiations.
Plan a selective harvest by calculating yield for different average log-diameter classes.
Verify buyer cruise estimates against your own stand measurements.
Help forestry students learn the differences between log-scaling rules.
Quick cruising sanity-check during field work.

Frequently Asked Questions

Last updated: 2026-05-29 · Reviewed by Nham Vu