Seems a bit chicken-and-egg there.
Seems a bit chicken-and-egg there.
Even a poorly fitted bra will give a better starting point than measuring braless.
And really, that's what this is: A starting point. Go with the best starting point that is available to you. You already are going to try on all of the ones that might work, you might as well narrow that down.
If you're wearing a properly-fitted bra, surely you can calculate your bra size by just asking the person who fitted it what size it is.
It's like buying a pair of jeans from five companies in the same waist size and leg lengths. Some will be tight around the waist while another fits well.
If bras are anything like shoes.
If you are buxom enough, you might not be able to afford or find an array of bras. If I buy in my size - generally around an H cup - bras easily range from $80-$120 each. I always have to buy a specialty bra. I had never found my size in an actual store in the US: I had to move to Europe for that.
All that said: Once I was able to find bras in my size, I did find that many are well-made, they fit and aren't rubbing nor digging in, and wearing them through the day hasn't really been an issue. At least, until they are wearing out and needing replaced.
they do loosen over time. most bras have 3-4 hooks, you start on the loosest and the only reasons you use the tightest is you got a bad fit or it's near time to throw it out