Measure around the narrowest part of your waist parallel to your belly button.
Men's Bottoms Body Measuring Guide
Measuring Guide
A.Waist
B.Hips
Measure around the fullest part of your hips,keeping the measuring tape straight.
C.Outside Leg
Measure vertically down from the narrowest part of your waist along the outer edge of your leg to your ankle.
D.Inside Leg
Measure the distance vertically from top of inner thigh to ankle.