As people have mentioned before on these threads, it all comes down to personal preference. But, I just dealt with this! I purchased my first Cartier YG classic love bracelet last weekend and agonized over the sizing. I posted about it on here too. The SA’s tend to push customers toward a more snug or standard fit, that was my experience anyway. I caved and went with her recommendation because she told me that 18 was far too big for my wrist. I purchased the 17 and went on my way. That night I felt like it was too tight and I obsessively worried about gaining weight, pregnancy, hot and humid summers, etc. so I went back the next morning and exchanged it for the larger size. My rationale is that larger is OK (there are tactics to prevent it from sliding up and down the arm too much) but too small is uncomfortable and can be unbearable in hot and humid climates especially during the summer months depending on where you live. I live in a tropical climate though and there’s virtually no winter. My vote is for the 16. Most people on here will suggest (and personally prefer) a more snug or standard fit. That’s how it was designed and marketed to originally fit but a lot of people including celebrities also prefer the looser fit these days. But go with what feels right. Try it on multiple times and don’t feel bad to exchange it if you’re not happy within a couple of days before it gets any scratches. This is an expensive purchase and you need to be satisfied. Customer service is usually good but it should be for that price point when purchasing luxury goods.