Most brands are true to size. I wear medium tees and all my rashgaurds are mediums as well. I've got some from Sirius, Hayabusa, Nogi, Manto, and Kaizen. As far as sizing goes, Manto is the only one that really sticks out, as it runs a little large. I've heard some people say Nogi runs small, but mine fits similarly to the rest of my RG's. I've found that the banding around the neck and arms is tighter, though.
Which brand specifically were you looking at? If you let us know someone here is bound to have had experience with them, and could give you some insight.
thanks
im down to 4 choices
paranah gear
venum
bad boy
warrior
145-150
so get a large in BadBoy?
I have a Venum long sleeve. I wouldn't go with a long sleeve though (it's personal preference after trying it out). Stick to short sleeve in either of those (don't know too much about Piranha gear) and you should be fine.
Warrior is pretty good with customer service too and has coupons often.
No, you would be a Medium in Bad Boy and it would fit you perfectly. I wear a Large in both the Bad Boy and Manto. I'm 6'2" and weigh 186lbs.
145-150
and I prefer LONG Sleeve, but I'm super paranoid about other peoples sweat and whatever else getting on me.