Your best bra size | And why it might be a totally new bra size…

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Every woman or girl has her own unique proportions. That’s why there are over 100 different bra sizes available. Here’s my quick guide to finding yours.

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What does a bra size consist of?

measuring tape explaining bra sizing

As I mentioned there are lots of different bra sizes, over a hundred!

Band sizes start from 60 centimeters or sometimes 65 centimeters, depending on the brand. Band sizes can go up to 130 centimeters.

The smallest cup size is AAA, you can shop for this size online.

measuring tape body
See my bra calculator or

Find your perfect bra with
Marks and SpencerM&S BraFit»

M&S Women AA-K » | Girls’ First Bras »

There are many bigger cup sizes that go up to cup O.

A bra size (for example, 70A), always consists of a number. That’s your band size. The letter stands for your cup size.


Are you going up or down a band size? In this case, the cup volume will also change.

  • 70A and 75B bras do not have the same cup volume
  • 70A and 65B do have the same cup volume

So, if you only want to change your band size? Always go up or down a cup size as well.

Which bra size is normal?

women wearing black bra

Every bra size is as normal as any size of breasts

Cup AA can be the first bra for a young girl. It can also be the cup size for a grown-up woman. We come in all shapes and sizes. It’s what nature is all about.

How will I know my bra size?

woman holding measuring tape to measure her bra size

Often I get the question ‘why do I have to know my measurements that precise?’

What does a little change in measurement do? Does it have to be that precise?


This is because only a slight change in measurement could mean a whole different bra size you might need!

Maybe your measurements fit nicely in a certain band and cup size. But many of us are in between two sizes. That’s two possible sizes.

Think of reasons why our body proportions (and breasts) may change. For example, losing or gaining weight. Measuring regularly is not a luxury.

Do I have to measure myself?

You don’t have to of course. Maybe you like to have a fitting in a lingerie store.

measuring bra size in a lingerie store

It doesn’t take much time to measure yourself at home. Knowing your size makes shopping for a bra easier.

Bra brands can have differences in their fit. Knowing your alternative sizes (sister sizes) will make shopping more fun.

What if I’m in between two bra sizes?


If you can choose between two band sizes, you choose the one you find most comfortable. Do realize a bra band should be quite firm. the most support from a bra comes from its band.

For example, you measure 77 centimeters. If you look at a bra size chart you could either go for 75 band or 80 band.

  • you choose 75B. You find the band is too tight and choose 80B instead. The cup volume of these bras is not the same.
  • in other to keep the same cup volume you need to choose 80A

Other articles you might like

Measuring guide on all topics
Why it’s best to handwash your bras
How to choose a comfortable bra band size?
About the average bra size UK
UK bra size chart
Why is my bra hurting me?
Bra size chart cups AAA-C
How will I know my cup size?

measuring tape body
See my bra calculator or

Find your perfect bra with
Marks and SpencerM&S BraFit»

M&S Women AA-K » | Girls’ First Bras »