I wear a large T-Shirt, I’m 5’10’’ and weigh 185lbs. I ordered a Large and it fits perfect over a T-Shirt or long sleeve T-Shirt. Would need an X-Large to put a sweatshirt under it. If you order your t-shirt size you should be good unless you need room for a hoodie or a belly haha.As for quality, this thing blew me away. The fit and finish for this price point is amazing. Easily a $160-$200 vest. YKK zippers, positive snap buttons and good Velcro on the cell phone pocket. Each inside pistol pocket has two button closure with an elastic band for a pistol and another one for and extra mag. Pistols at Glock 19 size and smaller should be no issue. Mesh lining on the back side to help vent between your back and the leather. The leather is not too thick but definitely a good quality leather.For the price, you CANNOT find a better quality vest. Would pass easily at any club house as a worthy cut. Plain back panel for large patches. Order this if you’re in the market, you will not be disappointed.SEMPER FI,Rooster