International Scale Calculator - Free Online Tool

Calculate your international scale with our free online tool.

Get accurate results instantly.

No signup required.

Last updatedHow we build & check our tools
Advertisement

How This Tool Works

The International Scale Calculator estimates log volume in board feet using the International 1/4-inch log rule. Enter the small-end diameter in inches, the log length in feet, and the number of logs. The calculator estimates board feet per log and, when more than one log is entered, the total board feet for the batch.

The rule models 4-foot log sections with a 1/4-inch saw kerf allowance and taper between sections, so it is meant for round-log scaling rather than finished board-size conversion.

  • Input: Small-end log diameter in inches.
  • Input: Log length in feet and number of logs.
  • Output: Estimated board feet under the International 1/4-inch rule.

Why This Matters

Log scale estimates are used to compare standing timber, sawlogs, and mill deliveries before boards are cut. A consistent rule helps buyers, sellers, foresters, and mills discuss expected yield from the same diameter and length measurements.

The International 1/4-inch rule is often preferred when a practical allowance for saw kerf and taper is needed. It gives a board-foot estimate for planning and pricing, but the final sawn yield can still vary with log quality, species, sweep, defect, and milling method.

Common Mistakes to Avoid

  • Do not use board dimensions as inputs: This calculator is for round logs, not nominal lumber sizes such as 2x4s.
  • Measure the small end: The diameter input should be the log's small-end diameter inside bark unless your scaling standard specifies otherwise.
  • Keep the rule consistent: Doyle, Scribner, and International scales can produce different board-foot estimates for the same log.

Frequently Asked Questions

Common questions about the International Scale Calculator - Free Online Tool

A board foot is 144 cubic inches (12"×12"×1"). Calculate as: (thickness" × width" × length") ÷ 144. This calculator handles the conversion automatically.
Advertisement