The Doyle Rule

Also known as the Connecticut River Rule and the St.Croix Rule ,the Thurber Rule and a few more names

Board feet per log

Small end and inside bark should be used for the Diameter

Deduct 4 inches from the diameter of the log as an allowance for slab;

Square one-quarter of the remainder and multiply the result by the length of the log in feet

Example1: A log that is 8” inches at the small the and inside the bark and 10’ feet long.

Take 4” from 8”: which is 4”. One-quarter of 4”: is 1”.

1” square is :1” And 1” times 10’ feet is : 10’ board feet .

Example 2: : A log that is 14” inches at the small the and inside the bark and 16’ feet long.

Take 4” from 14”: which is 10”. One-quarter of 10” is 2.5”

2.5” square is :6.25” And 6.25 times 16’ feet is : 100’ board feet .