It is 12 inches in circumference.
ten inch softball
ASA and USSSA women's softball is classified as a 12 inch softball
A 10 inch softball is used for little league but in 12u you change to a 12 inch softball.
In coed asa softball a 12 softball inch for men and an 11 inch for women softball.
same as baseball, but the actual softball is bigger in size than the baseball
12 inch ball for softball in age groups 16 and under