How Big Is a Tennis Ball? Official Size & Regulations

By Emma Wilson · January 30, 2027

A standard tennis ball has a diameter of 2.575 inches (6.54 cm) to 2.7 inches (6.86 cm), as regulated by the International Tennis Federation (ITF). This size ensures consistent performance in professional and recreational play.

Understanding the Size of a Tennis Ball

The size of a tennis ball is strictly defined to maintain fairness and consistency across all levels of the game. Whether used in Grand Slam tournaments or backyard matches, regulation tennis balls adhere to precise measurements.

Key Dimensions

Diameter: 2.575 to 2.7 inches (6.54 to 6.86 cm)
Circumference: Approximately 8.09 to 8.48 inches (20.55 to 21.54 cm)
Weight: 1.975 to 2.095 ounces (56.0 to 59.4 grams)

Regulations Set by the International Tennis Federation

The ITF governs the official specifications for tennis balls used in sanctioned events. These standards ensure uniformity in bounce, size, and weight.

Approved Ball Types

The ITF classifies tennis balls into three categories based on court surface and playing conditions:

Type 1 (Fast Speed): Used for fast court surfaces like grass and artificial turf
Type 2 (Medium Speed): Standard ball for clay and hard courts
Type 3 (Slow Speed): Larger ball for high-altitude play

Ball Type	Diameter (inches)	Diameter (cm)	Weight (oz)	Weight (g)
Type 1	2.575 – 2.7	6.54 – 6.86	1.975 – 2.095	56.0 – 59.4
Type 2	2.575 – 2.7	6.54 – 6.86	1.975 – 2.095	56.0 – 59.4
Type 3	2.7 – 2.83	6.86 – 7.19	1.975 – 2.095	56.0 – 59.4

Table data source:1

The data shows that while weight remains consistent across types, Type 3 balls are slightly larger to reduce speed at high altitudes. This adjustment improves playability under thinner air conditions.

Variations in Non-Regulation Tennis Balls

Not all tennis balls follow ITF regulations. Training aids, junior balls, and pressureless practice balls may differ significantly in size and performance.

Common Non-Standard Sizes

Red Stage 3 (Large): For young beginners, up to 3 inches in diameter
Green Dot: Slightly lower compression, same size as regular balls
Foam Balls: Up to 3.2 inches, used for safety in youth programs

Why Size Matters in Tennis Performance

The size of a tennis ball directly affects aerodynamics, bounce height, and player reaction time. A larger ball creates more air resistance, slowing down gameplay—especially useful at high altitudes where the air is thinner.

Consistent sizing ensures predictable behavior during rallies and serves, making it easier for players to anticipate shots and for equipment manufacturers to design compatible racquets and training tools.