“I'm a bigger guy and I could fit in 3X but like my clothes a little looser so I purchased the 4X. It fits perfect!!! A little loose so I can wear it tucked or in-tucked. Material is super thin and keeps you cool! and it has a lens cloth attached to the front is super awesome for when I forget mine while I'm out fishing. I highly recommend this and I will buy more in the future!! My only issue is the price is a little steep but I guess I'm paying for quality!!”