I love Lagos bracelets and have many. However, I've never had to choose a size before. Most bracelets are standard. I originally ordered the medium and found it to be snug. I exchanged the bracelet for a large which dangles more. If you like to wear a few bracelets at a time on one arm, I'd get the large. It allows for more "wiggle" room. Overall, it's a beautiful bracelet with a little weight to it but very comfortable. I wear it everyday.
I have numerous Lagos pieces and this is absolutely one of my favorites. It's substantial enough to be worn alone or paired with other Lagos or David Yurman bracelets. Easy to get on and off by yourself and works great with a small wrist. It looks a little stiff on line but it actually does have some movement to it.