Everyone's Racquet: Tennis Supplies and Service

Standard U.S. measure of string thickness. Most tennis strings are 15-17 gauge, with a few specialty strings being 18-20 gauge. The higher the gauge number, the thinner the string and typically measured in millimeters. Half-gauges are represented by the letter L, for "light". A 15L is between a 15 and 16 gauge. Thinner strings offer greater feel, power and spin potential than a thicker string of the same material and construction. Although the Tennis Industry Association has standardized gauge specifications, don't assume that all 16 gauge strings (or 17 or 18...) are created equal. One company's 16 gauge string may measure 1.28 mm, while another will measure 1.32 mm, which represents almost a half gauge difference.

Standard tennis grip sizes range from 4-1/8 to 4-5/8 inches. The accepted method for measuring your grip size is to hold the handle with an Eastern forehand grip (palm on the same bevel as the strings). The optimum grip size would allow you to fit your index finger between the palm and longest finger. Player preference obviously allows for exceptions to this rule. While many "experts" suggest using the largest comfortable grip size, keep in mind it's easier to increase handle size. In fact, most of today's racquet handles cannot be reduced in size. If you're between grip sizes, go with the smaller size and add an overgrip or have the grip built up with a heat-shrink sleeve.