Softball Dimensions: Ball Sizes, Field & Pitching Circle

Under the 2026 USA Softball rules, the official 12-inch ball must measure 11⅞ to 12¼ inches in circumference and weigh 6.50 to 7.00 ounces. Dividing circumference by π gives a rough diameter of about 3.8 inches; the rule specifies circumference, so use that official measure when checking a ball. See the USA Softball official rulebook.

There is not one softball size for every men's league. USA Softball rules include a 16-inch ball for men's 16-inch slow pitch; that ball must have a circumference of at least 16 inches and weigh at least 9 ounces. Other divisions use different ball specifications, including the familiar 12-inch ball. Check the league's rules and the ball's label before play.

USA Softball lists 60-foot base paths for fast pitch and modified pitch, 70 feet for slow pitch, and different base distances for 16-inch slow pitch (60 feet for men and 55 feet for women). These describe the distance from home plate to first and third base under the listed rules. Outfield fence distances and field layouts can vary by division, venue and local rules, so there is no single rectangle that describes every adult softball field.

The USA Softball dimension table specifies a pitcher’s circle with an 8-foot radius, which is a 16-foot diameter. A radius and a diameter are different measurements: the diameter runs all the way across the circle through its center. The required pitching distance and other field markings depend on the division; consult the current rulebook for the exact game format.