Please see the below table for recommended 'generic' batting pad sizes.
The measurement should be taken from just below the knee cap to just below the hip, in a straight line. This is only approximate, but this guide should be helpful to make the best choice on size.
Please be aware some brands may slightly differ:
Size
Length
XXS
38 - 43 cm
XS
43 - 48 cm
Small
48 - 51 cm
Medium
51 - 56 cm
Large
57 - 61 cm
XL
62 cm +
Arm guards, chest protectors and groin protectors are only available in limited sizes so please choose the most suitable size.