Written by:


May 31, 2023

I’m sure you’re aware of the benefits to wearing the correct size underwear – the difference it can make to your figure (it can make you look slimmer) and how well clothes fit you.  

You’re also probably aware of what happens if you don’t wear the right size bra –  the bad posture, the terrible back ache, and the ill-fitting clothes.  

But despite this, there's a high chance that you're not wearing the correct bra size, but I'm hoping to fix that with this blog post.  So read on to find out if you're wearing the incorrect bra size, and correct it if it's wrong. 

If you want help figuring out which bra SHAPE is the best for your bust, head on over HERE

bra terminology


This wraps around your back and is what should provide the majority of the bust support.  In fact, it should be providing around 90% of the support!  This is sized numerically - 28, 30, 32, 34, 36, 38 etc...


These help keep your bra in place.  They support your bust, however, they are not supposed to completely support it!  If you keep having to tighten your bra straps to keep them in place...you are probably wearing the wrong bra size.  But more on that later!


The cups are what hold your breast.  They come in a variety of shapes offering a variety of coverage and support.  They are sized in letters (A, B, C, D , DD etc...)


These aren’t just decorative, they help to shape and support the breast.

centre panel

This is the section between the cups that helps provide support and shape.


This runs along the edge of the cup and provides extra support for the bust, as well as helping keep the breast in the cups


1/   The cups of your bra ride up when you reach up

If this happens then the back measurement is too big for you.  Try going down a size at the back…and if you do that, go up a cup size as well, to make sure the cup fits you the same.


If the straps are falling down, it's a signal that the band is too lose so is riding up and making the straps loose.  Try a smaller band size (and again, go up a cup size to make sure the cup fits you the same)

3/    the band is riding up

If the band is riding up, then you're straps are probably falling down, too.  Go down a band size, and up a  cup size.


When the cups ride up it's because the band is too loose.  Go down a size in the band to make sure the bra stays put.  It can also be a sign that the cups are a size too big so bare than in mind and consider experimenting with a smaller cup size too.


If this is happening, either the cups are too small for you, or the band is too small.  Or both!  First try going up a band size, and if that doesn't solve the problem, go up a cup size.


This suggests that the cups are too big for you, or the band is too big.  It can also indicate that you're in the wrong style of bra for your bust shape.  If you think the band size is correct, go down a cups size.

how to determine the corect bra size for you

If you’ve identified that you’re probably not wearing the correct size bra, good!  You're one step closer to being more comfortable in your bra!

But before you can correct the size, you need to identify what needs correcting - is it the band size, or the cup size...or both?

The best way to do this is to use one of your own bras (not a strapless or padded bra, just your bog standard, everyday bra) a starting point, and refine the fit until it’s correct.

Pop your bra on, move your arms around, and then stand in front of a mirror and check these areas one by one:

check the cups

The cup size is too small if:

  • the cups are digging into your breasts
  • If there is any bust bulging out of the cup (check the top and the side - all your breast should be inside the cup).
  • The center panel is sitting away from the chest.  If there us a gap between the center panel and you, the cups are too small.

The cup size is too large if:

  • The cups are gaping
  • the cups are loose or baggy

check the band

Next we need to check the size of the band.

The band size is too small if:

  • It is digging in uncomfortably and you’re bulging out over it - if it is digging in but is NOT uncomfortable, then it is probably fine
  • The cups of your bra are flattening your bust and causing your breasts to bulge out - they should lift and support your bust, not flatten them.

The band size is too large if:

  • You hook your thumb under the back of the bra, pull it away from your back, and there is no resistance. 
  • You can easily fit more than two fingers under the band.
  • Your straps fall down when you move around. The band should be tight enough to keep your straps in place.  If the straps are falling down, it isn't that the straps need tightening, it's the BAND that needs tightening.

Once you have identified what is wrong with your current bra size, you can correct it. This is often the part that confuses people, but don't' worry it's quite simple.

The rule of thumb when correcting a bra size is:

If the cup size is incorrect but the band is correct

You simply go up or down a cup size, depending on whether the cup was too small or too large.

If the cup size is correct but the band size is too small

You go up to a larger band size, AND you down a cup size.  You must do the two things.

If the cup size is correct but the band size is too large

You go down to a smaller band size, AND up to a larger cup size. 

If both the cup size and tha band size are incorrect

First alter the band size, and if that doesn’t make a difference to how the cup fits you, alter the cup size.


It's important to note that you must adjust the cup size every time you adjust the band size to make sure that the fit of the cups remains the same.  If you don't adjust the cup size it will be incorrect.

making sure the new size is correct

Once you’ve uncovered your new bra size, it’s a good idea to head to your local lingerie department to test it out! Failing that, order some bras online and try at home.

When you put the new bra on, check the following:

  1. 1
    Are the cups filled well, and does the underwire completely encase your bust?
  2. 2
    Does the center panel sit flat against your sternum?
  3. 3
    Are the straps tight enough to stay put, not so tight that they dig in
  4. 4
    Does the band lie horizontally across your back?  It should be no higher than the front of the bra, and tight enough to support your bust almost entirely.

Wearing the correct bra size is SO important when it comes to your health, but it's also an important factor in how well your clothes fit.

If you're not sure whether you are wearing the correct bra size, and you don't have the time to figure it out at home, alone.  Book in for a fitting at your local lingerie boutique or department store.  It's typically free, and is well worth it.

Hi, I'm Niki

author and personal stylist

Over the past 18 years I’ve freed thousands of women from the frustration of disappointing outfits, by showing them how to dress to make the most of their shape, and helping them build a closet that's easy to use and fun to wear.  My blog shares the tried and true tips and knowledge I've developed, to help you stop wasting money on disappointing clothes, and build a closet you enjoy wearing.

You can find out more about Niki here

And you can get in touch with Niki here