In tailoring, the inseam is the seam that binds the length of the inner pant leg. The distance from the bottom crotch to the lower ankle is also known as the inseam. The inseam length determines the length of the inner pant leg to appropriately fit the wearer. In the UK this is usually known as the inside-leg measurement (for trousers fit). Inseam length is also key to determining optimal bicycle seat height adjustment. 0.88 x inseam = distance from seat to bottom bracket.