1. Make sure the cups are smooth and they lie flat against your chest
If the cups are wrinkly, the bra is probably too big for you. If you find out that your breasts are spilling out, then you need a bigger bra.
2. Make sure the band of the bra lies straight against your back
The band of your bra should lie horizontally against your back in a straight line. If the band of your bra rides up, then it is not your size.
3. Make sure the straps are not too tight
The band provides support and not the straps. If you’re relying on the shoulder straps to keep your breasts lifted, you may need a smaller band size.
4. The underwire should not dig into your skin
If the underwire of your bra causes you pain in any way, then you need to find a larger size.
5. There must be no boob bulge
If your breasts spill out of your bra, it means that you need a bigger bra.
6. The area between the two cups must lie flat against your chest
If the area between the two cups is floating, then the bra is definitely not your size.