1. Is your underwire sitting away from your chest wall?
This means your cups are too small. Your underwire should fit firmly against your chest without any gaping. Assuming your straps are properly adjusted, you’ll know you’ve found the right band fit when you can lift your arms over your head without the underwire rising up.
2. Are your breasts bulging out over the top, sides, or bottom of your cups?
You should probably go up a cup size. The cup should hold your entire breast without the dreaded quadra-boob.
3. Is your strapless bra slipping down?
You need to go down a band size. In fact, you may need to go down a few band sizes. With only the band to hold your chest up, a proper, firm fit is essential if you don’t want to spend the whole night hiking up your bra. [Read More The Right Bra]