Log Scale Calculator

About the Doyle/Scribner/International Log Scale Calculator

A log scale calculator assists foresters, timber buyers, and sawmill operators in accurately valuing commercially harvested timber. Instantly compare Doyle, Scribner, and International rule estimates for any log dimension, enabling fair stumpage negotiations, accurate inventory tracking, and precise load ticket generation for logging operations.

How it works

1. Select the desired log scaling rule: Doyle, Scribner, or International.
2. Input the length of the log in feet and the diameter inside the bark at the small end in inches.
3. View the estimated yield in board feet to calculate raw material value for timber sales.

Frequently asked questions

What makes the International rule different?

The International rule accounts for a standard saw blade kerf and log taper. It yields an estimate very close to the actual lumber produced by modern mills.

Why do buyers prefer the Doyle log rule?

The Doyle rule heavily penalizes small-diameter logs, underestimating their volume. Buyers prefer it because they often get more lumber out of small logs than they pay for.

How does the Scribner rule estimate volume?

The Scribner rule is based on diagrams of circles drawn inside logs. It estimates the volume of boards that can be sawn but does not account for log taper.

Do I measure the log diameter inside or outside the bark?

All standard log scaling rules require measuring the diameter at the small end of the log, strictly inside the bark, because bark cannot be sawn into lumber.

References

• USDA Forest Service Log Scaling and Grading Rules
• Society of American Foresters (SAF) Mensuration standards