Approximately 75% of women are wearing the wrong size bra.  While this figure may seam outstanding, it becomes believeable when you
 consider the complexity of each women's shape and the variations in bra shape from style to style and manufacturer to manufacturer.

Also, provided the continuing change in a woman's shape due to water retention, diet, exercise and the natural aging process, a bra that once fit properly will likely continue being worn beyond its proper fit.

A properly fitted bra is comfortable to wear and, ultimately, will feel as if you are not wearing a bra. A woman should visit her favorite lingerie store at least twice a year and, ideally, each quarter to ensure her bra fits properly. 

 A Well Fitting Bra Should...

• Have the underband around your body firm but comfortable.
• Have the back and front of the bra level.
• Have the wires lying flat against your rib cage, enclosing your breasts without rubbing or digging into your breast or armpit.
• Have a smooth outline, without bulging at the top or sides, or wrinkled cups.
• Support the weight of your breasts mainly with the underband and cups of the bra.

Some common bra fit problems and what to do to get a better fit:

• Wrinkled cups: Try going down one cup size.
• Breasts spilling out of cups: Make sure you are wearing the right size and style bra for you. Try a full coverage bra, or go up one cup size.
• Falling straps: First try adjusting the straps. Adjustable bra straps may move when you wash your bra. If that doesn't work your breasts may not be filling out the tops of the cups, so try going down a cup size. Or, you may be wearing a bra with straps place too wide for your shoulders. In that case try a bra style with straps closer together, like a racerback bra.
• Strap marks: Try loosening the straps. If that doesn't work you probably need a bra that provides more support, perhaps with wide padded straps.
• Band rides up in back: Hook the back closure on the next tighter setting, or loosen the bra straps. If that doesn't work go down one band size.
• Under wire digging in under the armpit: Your cup is too small, the under wire should encase the breast not dig into it.  You need a bra with a bigger cup size.
• Bumpy silhouette under clothes: Cup encasing breast is too small and so causes breast to overspill.  You need to increase your cup size, until you have a smooth silhouette.