How to Choose the Right Softball Size and Weight

Softballs are not all the same. They come in different sizes, weights, and compression ratings depending on the type of game, the age of the players, and the governing body regulations. Using the wrong ball in your league is not just against the rules. It affects how the game plays and how safe it is.

The Two Main Sizes

11-Inch Softballs

The 11-inch ball is used primarily in youth fastpitch and some youth slowpitch leagues.

It is slightly smaller and lighter, which makes it easier for younger players to grip, throw, and hit. Most youth leagues use the 11-inch ball for players up to age 10 or 12. Standard weight is between 5.875 and 6.125 ounces.

12-Inch Softballs

The 12-inch ball is the standard for adult and high school fastpitch, adult slowpitch, and most competitive play from 12U and up. Standard weight is between 6.25 and 7 ounces.

Fastpitch vs Slowpitch Balls

Fastpitch Softballs

Designed for higher-speed pitching with solid cores and leather or synthetic covers.

For high school and college fastpitch, the standard is a 12-inch, .47 COR / 375 compression ball.

Slowpitch Softballs

Come in a wider range of performance specifications. Common specs include .44 COR / 375 compression for ASA/USA Softball play, and .52 COR / 300 compression for some USSSA and NSA leagues. Always check your league rules.

Core Construction

Solid Polyurethane Core

Most common in modern softballs.

Consistent performance across temperatures. Used in most competitive balls.

Cork/Rubber Composite Core

Softer feel, popular in recreational leagues. Generally less expensive.

Kapok Core

Found in very inexpensive practice balls. Soft, do not fly far, break down quickly. Fine for casual backyard play only.

Cover Material

Leather covers provide better grip and last longer.

Synthetic covers are less expensive and more water-resistant. Most competitive leagues require leather-covered balls for official games.

Seam Type

Raised seams are more common in fastpitch because pitchers use seam height to generate spin. Flat seams create less air resistance and are common in slowpitch.

Choosing by Age and League

Youth Fastpitch 8U and under: 11-inch, low compression, synthetic or leather cover.

Youth Fastpitch 10U: 11-inch, .47 COR / 375 compression, leather cover.

Youth Fastpitch 12U and up: 12-inch, .47 COR / 375 compression. This is the transition to full-size.

High School Fastpitch: 12-inch, .47 COR / 375 compression, NFHS-approved, leather, raised seams.

College Fastpitch: 12-inch, .47 COR / 375 compression, NCAA-approved, leather, raised seams.

Adult Slowpitch ASA/USA: 12-inch, .52 COR / 300 or .44 COR / 375 depending on classification.

Adult Slowpitch USSSA: 12-inch, various specs depending on division.

How to Read Ball Markings

Every approved game ball has markings stamped on the cover: governing body stamp, COR rating, compression rating, and ball size. If the ball does not have clear markings, it may not be approved for competitive play. When in doubt, ask your league administrator which specific ball model is approved.