We provide actual measurements because letter sizes, such as S, M, L, XL, or even numbered sizes, etc, are meant as search-able guides only and should not be used to determine a garment's fit, since these vary greatly from manufacturer to manufacturer, change over time, and can be affected by use and washing on previously owned garments.  You should measure a similar garment which currently fits you, note it's measurements, and compare to those provided in our item measurements.