I always wear small tops. 5'4" 34B athletic. I was thrilled that the fabric isn't as sheer/see-through as I feared. My white bras don't show through at all. However, the back drops so low that all of my bras show, so I choose fun, strappy sports bras to wear underneath. Also, it's definitely loose fitting. My preference would be that it is cut just a bit slimmer - so I gave it 4 stars instead of 5. Maybe I'd have been better off with an XS for the first time ever? Regardless, this shirt is cute, super light and breathable.