I find this as a good tool, but do their sizes run small? If I would buy the size they told me to, I would have no support whatsoever. I tried the panty one too and that gave me a size of 4 times bigger than what I wear now, and I'm quite comfortable with my sizes.
Maybe I will try this for my daughter as the only bra she found that fits her good is the Hanes All over Comfort.