Yoga balls, also known as exercise balls, stability balls, or Swiss balls, come in various sizes. The size of a yoga ball is typically determined by its diameter, which can range from 45 centimeters (18 inches) to 85 centimeters (34 inches) or even larger.The most common yoga ball sizes are 55 centimeters (22 inches), 65 centimeters (26 inches), and 75 centimeters (30 inches). However, there are smaller and larger options available to accommodate different body sizes and exercise preferences.