1. Does the band of your bra rides up?


A band that rides up your back is a big, big red flag! Surprisingly, a lot of smaller-framed women tend to have this problem because (often due to a lack of options) they buy bras with bands that are too large for their petite figures.

Your band should be cozy yet snug, plus you should be able to slip one or two fingers beneath it, the right band ought to be somewhat level all the way around your body. It should also fit nicely on the middle hook, letting you extend to the outer hook if you gain some weight and the inner hook if you lose a little.


2. Is there a gap in between your boobs and bra?

There should be no gaps in the front, instead, the fabric between your breasts should lie flat against your skin. If it doesn't, you're probably wearing the wrong-size band. Get a smaller one

 

 
  
3. Does the band cuts into your skin?

If the band digs into you and creates back-fat bulges or red marks on your torso, it’s too tight and you need to move up a band size.

 
4) Is the breast tissue bulging from the edges of the cups?


Read full article here. http://www.dsuperwoman.com/2014/03/are-you-wearing-right-bra-size.html?m=1