Spike's Calculators


Early Log Rule

Spike VM

This rule appeared about the same time as the Doyle log rule, and its results are identical to those of the Doyle log rule.

  1. measure the diameter on the small end of the log in inches
  2. subtract 4 inches from the diameter
  3. multiply this amount by half of the remainder
  4. multiply this result by the length of the log in feet
  5. divide the previous amount by 8
  6. the result in board feet

An Early Log Rule Calculator

Length of Log in Feet ft
Diameter Log Small End in Inches in


Board Foot Result bf


  1. enter the small end diameter of the log
  2. the length of the log in feet


  1. the volume of the log in board feet

Example Calculation:
The diameter measured at the small end of the log is 24 inches, and the log is 20 feet long
24 - 4 = 20
20 * 10 = 200
200 * 20 = 4000
4000 ÷ 8 = 500
The log contains 500 board feet

If you have any questions or comments please Contact Us
Privacy Policy
© 1998, VmNet.