how do you know what size you are?
MARIA M Whatever size your hands are they fit perfect. I am 5'9" and wear Medium and my husband is 6'4" and wears 2xl and size 15 shoes, and the size is a perfect fit. We use these gloves for kitesurfung, kayaking and SUP in Hawaii, California and South Padre Island. All our friends want these gloves and we keep buying more beause we give them away.
JOE H i had a friend loan me some before i bought mine. they were L and were too small so i bought XL and they fit great. you can usually tell by your shoe size. my wife ordered L and she is a size 8 mens and i'm a 10 1/2.
PATRICK B Medium works for me in work gloves so I transfered that logic to dive gloves I also like them snug.
DEREK J I'd suggest trying on a golf glove to help you determine your size. I use mine for jet skiing in the cold weather and the XL was just right. Nice thing is you can use the velcro strap to tighten over your wrist. I'd recommend a size larger if your in question. Gloves are very nice.
JOHN H I sized my gloves as if they were golf gloves, somewhat tight. I would normally buy XL winter gloves, but I bought these in the Large size.