Size Guide As each brand and item of clothing has unique size, the fit of the items can vary a lot. Top Measurements For all tops (shirts, jackets, vests, polos, etc) we measure the items in two ways: A. Pit To Pit.  We lay the item on a flat surface and measure from the bottom of each armpit to the other armpit. B. Length To get this measurement we lay the item on its front, and measure from the very bottom of the garment up to the bottom of the collar.  If you are unsure please get in touch. For bottoms we supply the waist and length.  Bottom Measurements Our measurements for bottoms (jeans, tracksuit bottoms, shorts, etc) are taken from the manufacturers measurements on the inside tag of the bottoms. Shimano B.O.C Cycling Top Jersey - White - XL