How to Find Your Perfect Bra Size

How to Find Your Perfect Bra Size

You try on a new bra, and the fit’s not perfect. So, what do you start changing? Your band size? Your cup size? Both? Here’s the answer.

Put Your Bra on Correctly Before Checking the Fit

The first thing you should always do with a new bra is make sure you’ve put it on correctly.

Lean forward, make sure your breast tissue is up and in the cups, and that the tips of your breasts are in the apex of the cups.

Then stand up.

Check Your Bra Cup Size First

The #1 bra fitting mistake women make is being in a cup size that’s too small.

So, assess your cup size first. Here’s why.

Changing your cup size is a small change — only 1” difference in your total body circumference.

So, while keeping the same band size, go up or down one cup size at a time to see if your fit is improving.

And, if you’re going up in cup sizes, I always recommend going up until you find a cup that’s too big.

Signs Your Bra Cups Are Too Small

Here’s an example.

Our model is in a size 34D bra. Many may think her bra fits just fine. It doesn’t.

Underwires are on top of her breast tissue instead of in her breast crease.

This is a full coverage bra, but on our model, it looks like a demi bra.

Her cups are too small.

So, let’s increase her cup size while keeping a 34 band:

34(D2), 34(D3), 34(D4),

and maybe 34(D5),

and maybe 34(D4).

This cup fits.

So, now we have her cup size — D3 on a 34 band.

So, now we have her cup size — D4 on a 34 band.

So, now we have her cup size — D5 on a 34 band.

How to Find the Right Bra Band Size

Signs Your Bra Band Is Too Big

But the back shows her band is way too large.

The #2 bra fitting mistake is being in a band size too big which can also cause your straps to fall off your shoulders.

A band size change is a 2” adjustment, and also changes the placement of your bra straps on your shoulders.

So, going up a band size also moves your bra straps closer to your shoulders.

Use Sister Sizing When Changing Band Size

Now, when you change your band size, you need to understand sister sizing — and this is where many women get confused.

Changing a band size means you must also adjust your cup size to keep the same cup volume.

This sister sizing chart explains what I mean.

How to Keep the Same Cup Volume

Back to our model.

We left her wearing a 34 band and a D3 cup size.

We left her wearing a 34 band and a D4 cup size.

We left her wearing a 34 band and a D5 cup size — right cup size but her band is big.

So, we need to move up a cup size when moving down a band size to keep her cup volume the same.

To keep her cup volume the same and reduce her band size, we move from a 34(D4) to a 32(D5).

...we move from a 34(D5) to a 32(D6).

...we move from a 34(D3) to a 32(D4).

Cups fit, but the band is still a little too big.

Move to a 30(D6).

Move to a 30(D5).

Her cups fit, and the band is properly tight.

What a difference from her starting point.

Our model looks terrific in her perfect bra size, has much better support with a lifted and shapely bustline.

The Right Order for Finding Your Perfect Bra Size

You too can find your perfect bra size.

Just remember to first find your cup size. Then, follow the sister sizing rules to find your band size.