Measure yourself in hips. Our model is approx. 100 cm wide.
Choose one of your very comfortable panties. Measure, how wide they are.
Our model panties have 2x36 cm. How does she fit into them?
Well, that's because panties are stretchy.
Now measure yourself below bust. Our model is 77 cm wide.
Now measure your bra, how wide is it?
Our model's (old) bra had 74 cm. Quite ok, but remember what we said about panties being stretchy?
You can stretch your bra the same way. The band will be then as comfortable on your body, as panties band (provided that the cups are good size).
But look, our model's bra stratched up to 94 cm! Isn't it more than15 cm too wide?
Yes, it is. That's way she does not wear this bra anymore. Convinced?