Did you know that 80% of women are wearing the wrong bra size? It’s true!  I was one of them! A research study published in the  Chiropractic & Osteopathy journal showed these results. Admittedly, the study is not that recent, but  I couldn’t find any newer studies. But the results were that most (80%) women wore incorrectly sized bras: 70% wore bras that were too small, 10% wore bras that were too large.

Did you also know that there is a specific formula for determining your bra size? It’s not JUST about measuring the band size and cup size! There are actual calculations that need to be done. I’ll explain in a bit.

Recently, at a meeting of my  Polka Dot Powerhouse group (an international networking group of professional women), Jocelyn, one of our members, did a presentation on how to correctly fit a bra.  Jocelyn actually worked as a professional bra fitter at Bergdorf Goodman in New York City as their expert fitter in the lingerie department.

Before we get to the nitty-gritty of determining your best size, there are a few things you should know.

Most of the support comes from the band.

Jocelyn mentioned that one of the most common problems is that many women choose band sizes that are too big and cup sizes that are too small! This was MY mistake. This provides no support! When the band is fitted correctly, it should anchor the weight of the breasts, providing 90% of the total bra support. The band should stay level around the rib cage throughout your day. This also makes it easier for larger-busted women to wear undergarments like a bralette.

When you’re wearing the correct band size, you should be able to fit your finger between your back and the strap with only about an inch of stretch.  Keep the bra on the middle clip, because the others are for when you are between sizes or when the bra stretches out.

If your bra straps are slipping off your shoulder, your cup size might be too big.

Another sign that your cup size might be too big is if the center panel of your bra between the cups, is not laying lat against the middle of your chest. There should not be a gap there.

If your bra straps are digging into your shoulders, it might mean that your cups are too small…or your band is too big… or both!

The straps are not really designed to do the heavy lifting (pun intended); 90% of the support comes from the band. And the cups are designed to hold the breast tissue i nso that it’s not overflowing the cups and adding extra weight to the straps. Also, when you look in the mirror, If your straps are pulled so tight that they’re yanking your band up, the band is probably too big or has become too stretched out to do its job.

You also need to know your “sister size”.

Because there are variations in brands and styles, or just because your regular size isn’t available, you also need to know your sister size.  If a bra doesn’t fit well in your regular size, it might work in your sister size.

The rule of thumb for this is that If you need to go up in the band, you’ll go down in the cup and vice versa. For example, if your regular size is a 34C, you could possibly fit a 36B or a 32D. If you’re a 32C, you might find bras that fit better in a 30D or a 34B.

Finding your correct size. 

How to measure your band size*

Start by putting on your best-fitting underwire bra—then, lift your breasts up so the tape measure is directly under them. Wrap the tape measure around your rib cage, making sure it’s straight across your back, parallel to the floor.  This measurement should be snug!  If that number is under 36″ then you add 5″. For example, if you measure 28″, add the 5″  which makes it 33.  If the band is over 36″ you will add only 3″ to that number. If it’s an odd number, round up to the next even number.

*Victoria’s Secret has a completely different way of measuring.

woman measuring her band size with yellow measuring tape

How to measure your bust size

Wrap the tape measure around yo (again, making sure it’s straight across your back and parallel to the floor) and place it at the fullest part of the bust (the point farthest away from the chest wall, where your nipples are). This measurement should be fairly loose.

Woman measuring her bust size


How to calculate your cup size

Subtract your band measurement from your bust measurement, and that’ll give you the cup measurement. Every inch difference between your band and cup measurement is a cup size. The first inch is an A (if the measurements are the same, that would equal an AA cup) the second is a B, the third a C, the fourth a D, and so on. The cup sizes are AA, A, B,  C, D, DD, DDD, F, G, H

If the measurement is the same as the band – AA
If 1 inch larger – A
If 2 inches larger – B
If 3 inches larger – C
If 4 inches larger – D
If 5 inches larger – DD
If 6 inches larger – DDD

How to put on your bra correctly

An article in Oprah Daily recommended this method when putting on your bra – the “stoop, swoop, and scoop” method.  “Lean forward from the waist, allowing the breasts to drop into the cups (stoop), then, with the opposite hand gently bring the breast tissue forward from the back towards your cleavage (swoop)…scooping it in front of, and on top of the underwire into the cup (scoop). Frederika Zappe, a national fit specialist, said that when you do this, you can often go down an entire band size.

If you’re wearing a bra with underwire, it should surround the entire breast, with the back end of the wire sitting behind the breast tissue on the bone, not on the tissue itself. This will ensure the breasts are fully supported.

For the curvier girl, it’s important to have a firm bottom cup. This will make the cup ‘droop proof’.


It’s best to use a lingerie or bra bag when laundering and to wash on the “delicate” setting, using cold water and  an alcohol-free, gentle detergent. Always hang or lay flat to dry. Do not use the dryer!


Always clasp the back (mostly to protect other items) and lay them either flat (as in the photo below), or hang them by their straps. While it may seem okay to fold them in half and stack (that’s how I was storing them), that actually ruin the center gore. Amazon has a natural wood bra holder hanger that will hold up to 10 bras as well as a 3 set underwear organizer that look pretty good. You can even get a closet hanging bra organizer with dual-sided pockets.

close up of bras stored in a white drawer, one in front of the other

So that’s it!  Let me know if you used the calculations and what you found out!

PS I had been wearing a 34C. Turns out I needed a 32DD!


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