How to measure your bra size

From the collection Marks & Spencer AA-K cups | See collection on M&S

  • Are you not happy with your bra right now?
  • Or maybe you’ve never ever had the feeling of wearing a well-fitted bra before?
  • Maybe your body and breasts have changed, and so may have your bra size?
  • Looking for your first bra?


Bra Measure Guide

  1. How to measure your bra size?
  2. How often does our bra size change?
  3. Why you should wash your bras by hand
  4. What are bra sister sizes?
  5. How to know my best bra band size?
  6. Bra band size too small
  7. Small bra size chart | cups AA-B
  8. Shouldn’t I go to a lingerie store?

You can use my calculator or try the M&S Calculator and see your recommended bras.



1. How to measure your bra size

Take about 10 to 20 minutes to do your measurements. Only a well-fitted bra will turn you into a bra lover.


Step 1   Measure your band size

Measure your band size
  • put the tape measure around your underbust
  • write down the inches or centimeters

Step 2   Measure your cup size

Measure your cup size
  • put the measuring tape around the fullest part of your breasts
  • don’t pull too tight
  • write down the inches or centimeters

Measuring your underbust and bust size yourself isn’t difficult. Not at all.

Do have a bra fitting if you prefer, or let someone help you. Most important thing is that you DO take action.

You’d rather go for a bra fitting? That’s fine. My advice is to write down the measurements after your fitting.

Knowing your sizes will give you more control when shopping for a bra. You might be just in between two different bra sizes. Also depending on the bra style and brand you might wanna to try them both.


Researches keep telling us that over 60 to 80 percent of women do NOT wear their right bra size

Use a bra size chart or try the bra calculator Marks & Spencer |
Go to M&S bra size calculator »


2. How often does our bra size change?

Your bra size may change in life through several causes.

We can all think of reasons why our body, and therefore our breasts, can change.

Like, the weight that you gain or the weight that you lose. Read more about why your bra size may have changed and how will you know.


3. Washing bras by hand, why should you?

A washing machine and bras don’t mix that well.

Likely you are, or have been tempted to use the washing machine once in a while.

Washing your bras regularly (by hand) is needed to clean and strengthen the elastic fibers. And did you know it’s best to rotate between your bras and give it a rest?


4. Bra sister sizes do I have one?

tree bras flat down

You too might fit different bra sizes.

Most women are just in between two different bra sizes. What will you choose then?

Going up or down a band size changes your cup volume as well.

For example, the sister bras 40C and 38D have the same cup volume. Learn all about your bra sister size »


5. How to determine your best bra band size?

measure bra band size

Looking for your bra size? Always start with your bra band size first.

There are about 14 different band sizes available. Although not every brand has the whole range of band sizes 28 – 54.

You could be just in between two band sizes. How to determine your best bra band size? Because you definitely don’t want the band either be too tight or too loose.


6. Bra band size too small?

women adjusting her bra
A change of band size will change the cup volume

Most support from a bra comes from its band. So a firm band is what you should look for, but definitely not too tight.

What do decide if your bra band feels to small but you’re not sure what you need?


7. Small bra size chart

Ladies with AA and AAA cups!

You won’t find your cup in most size charts. It is likely you end up with a cup that is too big for you.

Be sure to check out a chart that includes AA cup, like the M&S size chart or use my calculator that starts from AAA cup.

Dobreva Front Closure Push Up Underwire Bra | AA-DD cups See details at Amazon.co.uk


8. Shouldn’t I go to a lingerie store instead?

Measuring at the comfort of your home.

Of course, you can go to a lingerie store to have your measurements taken.

My advice is still to write down the measurements so you’ll be able to check your sizes in a chart when needed.

I became a bra lover only after I learned about my own measurements and finding my bra size in a proper size chart.


My Guides
Bras for small breasts »
Bras for large breasts »
Sexy bras »



Researches say 60 to 80 percent of women do NOT wear their right bra size

Use a bra size chart or try the bra calculator Marks & Spencer |
Go to M&S bra size calculator »