Doyle Log Rule Calculator

The Doyle Log Rule Calculator helps estimate the board feet volume of a log based on its diameter and length using the Doyle log rule, which is commonly used in the lumber industry.

Historical Background

The Doyle log rule, developed in the 1800s, is one of the oldest log scaling methods. It was created to estimate the volume of lumber that could be sawn from logs, accounting for the saw kerf (the wood lost to sawdust) and other processing inefficiencies. Though it tends to underestimate the volume of smaller logs, it has been widely adopted in North America due to its simplicity.

Calculation Formula

The Doyle log rule calculates the volume (V) in board feet as follows:

\[ V = \frac{(\text{Diameter} - 4)^2 \times \text{Length}}{16} \]

Where:

• Diameter is the small-end diameter of the log in inches.
• Length is the length of the log in feet.

Example Calculation

For a log with a diameter of 20 inches and a length of 16 feet:

\[ V = \frac{(20 - 4)^2 \times 16}{16} = \frac{256 \times 16}{16} = 256 \text{ board feet} \]

Importance and Usage Scenarios

The Doyle log rule is vital for sawmills and forestry operations to estimate the yield of lumber from logs, facilitating fair transactions between log sellers and buyers. Despite its limitations with smaller logs, it remains a widely used standard due to its ease of use.

Common FAQs

1. Why does the Doyle rule underestimate small logs?

   • The rule was designed when sawmills had wider saw kerfs, resulting in more wood loss. This makes it less accurate for small logs, which have less wood to lose proportionally.

2. Can I use this calculator for all log sizes?

   • The Doyle rule is best suited for medium to large logs. For smaller logs, other rules like the Scribner or International 1/4-Inch rules may provide more accurate estimates.

3. What is a board foot?

   • A board foot is a unit of measurement for lumber, equivalent to a board that is 1 inch thick, 12 inches wide, and 12 inches long.