If those charts confuses you just as much as they confuses us, here's a breakdown:
Our shirts are very true to size. If you usually wear a size M, order a size M. If you like your shirts to fit a bit loose/oversized, then order the next size up.
WOMEN'S CUT TEES
SMALL: FITS SIZES 2-6
MEDIUM: FITS SIZES 6-10
LARGE/XLARGE: FITS SIZES 10-18