I am a female and ordered a mens size 2x and it is not skin tight but it is not largely loose either.  When they say they run small, they are not kidding.  I am a L to XL in womens tops depending on who makes them so I thought a mens 2 XL would give me breathing room since I only want it to avoid being sunburned when swimming.  My advice would be to seriously order a bigger size than you think you need.  The shirt is nice and comfortable but I fear the design will wear off with time and washing since it is just an iron on.  Over all I am happy with my purchase and it arrived on time with no problems.