Imperial System:

  WIDTH (inches) LENGTH (inches)
S 21 ⅜ 18 ½
M 22 ¾ 19 ¼
L 25 ⅛ 20 ½

 

Metric System:

  WIDTH (cm) LENGTH (cm)
S 54.4 47
M 57.8 48.9
L 63.8 52