Bra Size Guide

What is Sister Sizing?

Sister sizing is a quick and easy way to find alternative sizes for both band and cup that will give you the perfect fit. Different bra styles fit differently, and knowing how to determine your sister size can be an extremely useful tool when buying a bra.

Cup sizes are not uniform across the board, a D cup on a size 12 band would be a much bigger cup than a D cup on a size 6 band. As back sizes get bigger, the cups proportionately get bigger too.

If you go down a back size, you will need to go up a cup size - this is your sister size. For eg. If your bra size is 14D, but you want a firmer fitting band, your sister size would be 12DD. Similarly, if your band is too tight, you can go up a back size and down a cup size, your sister size would be 16C.

Why is my bra band riding up?

A telltale sign that your band is too big is if it starts riding up. Try going down a back size (don't forget to go up a cup size). Your bra band should sit firm and your breasts should be comfortably enclosed in the cups!

Why do my breasts spill out of the cups?

There's no bigger wardrobe malfunction than spilling out of your cups, if this is happening, you likely need a bigger cup size.

Why are my cups gaping and wrinkling?

If your cups are puckering and gaping, your cup size is too big and if there is extra room in the cups, you need a smaller size. Unless of course, you want a secret pocket.

Your cups can lose shape and wrinkle after washes too, so we always recommend washing your delicate bras by hand.

Stretch lace bras are an excellent choice if you want your cups to fit snuggly around your breasts. This lace hugs your breasts and moulds to shape of your curves, which is great if one breast is bigger than the other!

Why do my bra straps slip off my shoulders?

A simple explanation could be that your straps are too loose, first tighten your bra straps and check again. If they still slip off your shoulders, it might be because you have sloping shoulders. You can use a bra buddy to convert the straps to a racer back style or try a full cup bra that has straps that are more centred.

Why are my straps digging into my shoulders?

If your straps are digging in, they might be too tight, try loosening them a little. If the digging persists, this could indicate your bra band is not giving you adequate support and your shoulders are bearing the weight of your breasts. You can try a smaller band size for better anchorage.

1. Measure Your Band Size

To accurately measure your band, stand upright, wearing a non padded bra (don't wear a push up bra or minimiser), measure around your back and under your bust, where your bra band would sit. Make sure the measuring tape is level as it goes around your body, you want to measure for a snug but not tight fit.

Measure in inches: if you land on an even number, that is your band size. If it's an odd number, round up to the nearest inch to find your back size.

Refer to the chart below to find your band size in Australia.

2. Measure Your Bust

Wrap the measuring tape around the fullest part of your bust around the nipple area. Keep the tape flat and level as it goes around, you don't need to pull tight for this measurement. Round up to the nearest number, this measurement will help determine your cup size.

3. Calculate Your Cup Size

To calculate your cup size, subtract your band measurement from your bust measurement. If your band measurement is 34 inches, and your bust measurement is 38 inches, 38 - 34 = 4. Referring to the two charts above, your Australian band size would be 12 and the cup size would be the alphabet corresponding with the number 4 i.e D. Your bra size is - 12D

After properly measuring yourself, you may find that your bra size is quite different from what you have been wearing, usually the correct size is a little bigger than before. At Storm in a D cup we have the most comprehensive range of bra styles from leading bra brands, Panache, Wacoal, Freya, Fantasie, Elomi, Cake Maternity, Curvy Kate and lots more, specially curated for the D cup and up woman!