CHAPS: Chaps are not designed to put on like a pair of pants. Therefore a good fit in the thigh helps get you a best fit. Measure your thigh mid way down your thigh, not your upper thigh or you might just order a size too big in the waist. Inseam: Technically chaps do not have an inseam since each person wears them differently. The lower you buckle the chaps the longer the inseam.