7 inches (6.9 centimeters) in diameter and weighs about 2 ounces (57 grams).
A tennis ball is a small, round object that is used in the sport of tennis. It is typically made of rubber or synthetic rubber, and filled with air. The size and weight of a tennis ball can vary depending on the type of game being played. For example, regulation balls used in competitive matches must be between 2.57 and 2.70 inches (6.54 and 6.86 cm) in diameter, and weigh between 0.9 and 1 ounce (25.5 and 28 g).