Size Recommendations For Baseball Bats

Babe Ruth's first bat was 54 oz., before he finally settled at 40 oz. Ty Cobb and Joe DiMaggio swung 42 oz. bats, according to associate professor Daniel Russell at Kettering University in Michigan. Today's baseball bats are much lighter and more compact than those used by the great hitters of previous generations.

Rule Standards

Major League Baseball sets the rules from which most amateur leagues follow. Rule 1.10(a) states that the bat cannot exceed 2-3/4 inches in diameter and 42 inches in length. The NCAA follows the rule for wooden bats, though it allows for differently sized metal bats. Nonwood bats have a maximum length of 42 inches and their diameters cannot exceed 2-5/8 inches.
In terms of weight, the NCAA regulations state that a nonwood bat must weight three ounces less than the number of inches.

Bat Weight

The weight of the bat is one of the most crucial determinants of success at the plate. Russell, as well as the staff at the HRSInformer, write that bat speed creates longer hitting distance than the weight of the bat. The lighter the bat, the faster it can be swung. Based on his tests, Russell developed numerous formulas to determine optimal bat weight. Major League Baseball players should divide their height, in inches, by three and add seven and use this as their optimal bat weight. College and other amateur players should divide their height by three and add six to the number. High-schoolers should diving height by three and add one to it.

Bat Length

NCAA rules state the value of the weight in ounces must be three less than the value of length in inches. In professional baseball, the variable is two inches more than the weight in ounces. Longer bats can be more difficult to swing and control. The HRSInformer cautions shoppers against buying the wrong-sized bat, reporting "Younger players especially tend to want longer bats because they feel they can reach the other side of the plate while still keeping their distance from the ball. However, a bat that is too long can make hitting a baseball one of the hardest things you'll ever try."

Choosing the Right Size

The buyers guide at Dick's Sporting Goods offers two guidelines -- age, and height and weight. It recommends 34-inch bats for those age 17 and older; 32- to 33-inch bats for those 15 to 16 years old; and 31- to 32-inch to those 13 to 14.
A second chart breaks the optimal bat size down by weight and height. For instance, a 73-inch tall player weighing 175 lbs. should carry a 34-inch bat, while a player at the same height but at 155 lbs. should drop to a 33-inch bat.