The average rate of taper for Indiana trees is 1.5 inches in a 12-foot log. Thus, if the top diameter of the first log is about 16 inches, the top of the second log will be about 14.5 inches. Good judgment is needed in estimating taper since most trees will taper more or less than the average. Taper estimates will be improved by checking estimates with measurement of log diameters after trees have been felled. Sawlogs are generally estimated in even foot lengths from 8 to 16 feet.
Length depends upon the location of crook, defects, and utilization.
Logs suitable for veneer or special products are cut in both odd and even foot lengths. To find the number of board feet in any log, move down the left-hand column in the log rule until the number is found which equals the small end diameter of the log. Then move to the right in the table until directly below the log length. The figure in this position is the log volume in board feet. For example, a log 16 inches in diameter and 12 feet long contains 108 board feet.