Note: the following dimensions show the size of the pants. You could measure your similar pants then compare to this size chart to choose the best fit size.
Size Chart(Unit:inch)
28Wx31L:Inseam: 30''---- Front rise: 10''----Thigh: 21''----Leg opening: 12 ''
30Wx31L:Inseam: 31''----Front rise: 10''----Thigh: 22''---- Leg opening: 12''
32Wx32L:Inseam: 32''----Front rise: 11''---- Thigh: 23''---- Leg opening: 12 ''
34Wx32L:Inseam: 32''---- Front rise: 11''----Thigh: 24''---- Leg opening: 14 ''
36Wx32L:Inseam: 32''----Front rise: 12''---- Thigh: 25''---- Leg opening: 15''
38Wx32L:Inseam: 32''----Front rise: 12''---- Thigh: 26''---- Leg opening: 16''
40Wx32L:Inseam: 32''----Front rise: 12''---- Thigh: 27''---- Leg opening: 17''