I ordered according to the size chart. I should have listed to other reviewers who complained that the straps are too long. I don't know if they're too long, or the straps are cut too far out on my shoulders, but I have to adjust them every 15 minutes because the strap has fallen down my arm. The only reason I keep wearing them is to get some relief from my dreaded underwire bras. They would have otherwise been comfortable. As far as the support level is concerned, don't count on much. Theyre a step up from being braless, but nowhere near as supportive as my regular non-underwire bras.
I have another brand that is racer back style, and Ill just stick with that, in the future. I will not be reordering these.