Measuring the player's height, weight and arm length, determining her strength, and checking for any applicable league rules regarding material composition are important factors involved in choosing the correct baseball bat size. Baseball players also need to handle and swing the bat to ensure that its length and weight can be used comfortably and effectively.
Baseball bat sizing charts are available at Slugger.com and SportsAuthority.com. The charts require knowledge of the player's height and weight to calculate a range of correct sizes. Another method to determine the correct size is to hold the bat with the barrel end resting on the floor. If the player can rest the palm of her hand on the knob, it is the correct size. The player can also place the knob of the bat against her shoulder and if her hand reaches the barrel, then the bat fits her arm length.
The appropriate weight of the bat depends on the strength of the player. Typically, bigger and stronger players use heavier bats to generate more power. Smaller players need lighter bats to maintain bat speed through the swing.
Modern baseball bats come in a wide range of materials, including wood, aluminum, and graphite or titanium lined. Metal bats can provide advantages by allowing players to use longer or lighter bats and still achieve good, powerful contact. Most leagues have specific rules on the types of bats that players can use.