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Doyle Scale Formula:
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The Doyle Scale is a rule used in the lumber industry for estimating the board feet in a log. It's one of the most commonly used formulas in the eastern United States for calculating lumber volume.
The calculator uses the Doyle Scale formula:
Where:
Explanation: The formula subtracts 4 inches from the diameter to account for slab loss, squares the result, multiplies by length, then divides by 16 to convert to board feet.
Details: Accurate board feet calculation is essential for lumber pricing, inventory management, and fair transactions between loggers, sawmills, and wood product manufacturers.
Tips: Enter diameter in inches and length in feet. Both values must be positive numbers. The diameter should be measured at the small end of the log, inside the bark.
Q1: Why does the Doyle formula subtract 4 inches?
A: The 4-inch deduction accounts for slab loss during the milling process where the outer portions of the log are removed to create square-edged lumber.
Q2: How accurate is the Doyle scale?
A: The Doyle scale tends to underestimate volume for smaller logs and overestimate for larger logs compared to actual mill yield. It's most accurate for medium-sized logs.
Q3: When should I use Doyle vs other log rules?
A: Doyle is commonly used for hardwood logs in the eastern US. The International 1/4-inch rule or Scribner rule may be preferred for softwoods or in other regions.
Q4: What are the limitations of the Doyle scale?
A: It's less accurate for very small logs (under 12 inches) and doesn't account for log quality, defects, or taper. Actual mill recovery may vary.
Q5: Can this calculator be used for standing trees?
A: No, this calculator is designed for cut logs. Tree volume estimation requires different methods that account for height and form.