Wearing a good supporting bra stand in front of a mirror and measure straight across your back just under your breasts (see attached picture). It is important that the tape measure is a straight line if it does not that will add inches. Also, Do NOT wear an underwire bra for this measurement as this will throw off your results slightly. Having someone help with this will ensure a more accurate measurement. Add one inch to the resulting figure. This figure will be the band size.
-Cup Size #2
While wearing a good fitting, well supportive, non padded bra measure across the back and over the top of fullest part of your breasts. If the resulting figure is a fraction, then you will round up to the nearest number and add an inch if the number is odd. For instance for 30 and ½ inches you would round up to 31 and add 1 inch. If the figure were 27 and ½ you would round up to an even 28.
Take the band size and subtract it from the second figure. The difference between these sizes in inches determines the cup size.
½ – 1 A
1 – 2 B
2 – 3 C
3 – 4 D
4 – 5 E
5 – 6 F
-A great fitting bra shouldn't dig, pull, poke or otherwise cause discomfort. If it does, it's not the right size (or bra) for you. Make sure it feels comfortable when you are moving around.
- There shouldn't be any breast tissue spillage at the top, side or bottom of the cups. If there is, your cup size is too small. Try sizing up for a better fit.
-Straps shouldn't work too hard. Your bra's support comes from the band, not the straps. So be sure that you're wearing the correct band size. Too big, and your straps will end up taking the weight, which will cause them to put pressure on your shoulders and dig in.
-Is your band straight? Look in the mirror from the side. Your band should be at the same level all the way around your back. If it is riding up in back, it's probably too big. Try sizing down a band size or tightening your band.
-No gaping: The center front of your bra should lie flat against your breastbone. It should not lie on top of any breast tissue. If there's a large gap, you may need to go up a cup size.
-Band tightness: Your band should feel firm and secure, but you should also be able to slip two fingers beneath the band in back, and one in the center in front. If you can't, you may need to loosen your band a bit, or go up a size.
-Underwires: Underwires should lie flat at the front of your bra, against your ribcage. If you feel your underwire digging into any breast tissue, you should try a larger cup size or a different style.
-Bras stretch over time: Be sure you're wearing your bra on the loosest hook. Your bras can stretch with washing and wear, so when you buy a new bra, it's best to ensure it fits properly on a loose hook, so you can tighten it as needed.
-A perfect fit: Your breasts will feel like they are "sitting" in the cups, you will not feel any underwire pinching and your bra will feel comfortable and supportive. You shouldn't have to settle for a so-so fit. Sometimes you will have to go up a cup size or two. Don't let it concern you – sizes do vary among brands. Finding the perfect bra takes time and patience, but the way you will look (and feel) once you have found it will be worth all of your effort.