# International 1/4-inch Log Rule (Clark) Calculator

Calculate the amount of board feet in a log using the International 1/4-inch Log Rule online.

The International 1/8-inch Log Rule was developed by Judson F. Clark in 1906 while working for the Province of Ontario. In 1917 it was modified to allow for a 1/4-inch kerf. The International 1/4-inch Log Rule is considered to be the most accurate mathematical log rule for board feet calculation.

The first result listed is what the calculator is intended to calculate.

The conversions for the other volume measurements are derived from the first one.

Board Foot * 0.0833333 = Cubic Foot

Board Foot * 0.00235974 = Cubic Meter