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I'm 5'7, 125-130lbs, athletic build and ordered size 3. The arms were perfect length since I have a bit longer arms. It's such a cute, affordable staple piece for your wardrobe. It was a nice lightweight, silky material especially for these warmer months. It's not too tight or loose; if you like the looser fit, I'd size up from your normal size. I ordered black and it looks as advertised. So cute I'll be ordering other colors!