Suggested size chart:
If you are typically a size small, medium or large in tees, order S/M, typically XL in tees order M/L for a true to size fit. If you typically wear XXL in tees you can do the M/L in this, it will just not be as flowy of a fit as most unisex tees, it will fit more like a ladies tee.
I'm typically a size XL in tees and wearing the M/L here