Based on the measurement chart, I ordered a size small, but it was so long and baggy, much larger than other men's clothing of the same size. For reference, I am 5'7' and 135lbs. My chest is 36'. In the first 2 pictures I am wearing the men's small, and in the last 2 pictures I am wearing the women's medium. If you have similar body measurements and don't want a super baggy vest, consider getting the women's version of the vest in size medium. It's the perfect length and roomy enough that I can move my arms freely without having billowing extra fabric.
Rating: [5 of 5 Stars!]