Fairtex FGV18 Grappling gloves size [question]

I am wondering about the size chart on the FGV18 Fairtex gloves, it is specified that my knuckle width (3.15 in) is considered to be S size, but i have relatively big hands. The size chart is pretty confusing so if anyone has experience with those gloves, please let me know. Also is the size chart supposed to consider hand wraps? How did you determine your size, and is it a good fit?