How to measure your bra size

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Only a well-fitted bra feels supportive and comfortable. Check my measuring guide for advice.

1. How to measure your bra size

  • are you not happy with your bra right now?
  • never ever had the feeling of wearing a well-fitted bra before?
  • maybe your body and breasts have changed?
  • looking for your first bra?

Measuring your underbust and bust size yourself isn’t difficult. Do have a bra fitting if you prefer, or let someone help you.

You’ll need 10 to 20 minutes to do your measurements and look up your bra size in a chart or calculator.

Check your size in my bra calculator
of visit M&S for advise and size chart

measure tape bra size uk

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Step 1   Measure your band size

Measure your band size
  • hold the tape around your underbust
  • pull it a bit tight
  • write down the inches or centimeters

Step 2   Measure your cup size

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

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 try them both.

2. UK bra size chart and how to use it

How does it really work a bra size chart? It seems simple and it is in a way. But you could be in between two sizes. Take these 4 steps to find your best bra size.

3. How often does a 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.

Think of the weight that you gain or the weight that you lose. But there are different reasons why a bra size may change in your lifetime.

4. Why wash your bras regularly?

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

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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 them a rest?

5. 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 »

6. 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? Take some time to measure a couple of times because you definitely don’t want the band either to be too tight or too loose.

7. 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.

So, what do you decide if your bra band feels too small but you’re not sure what cup volume you need?

8. Small bra size chart

Women and girls with the smallest cup sizes often feel left out if they see a bra size chart.

That’s because size AA and AAA are often just not there in the chart! 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.

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9. Why measure at home?

Measuring at the comfort of your home.

Of course, you can go to a lingerie store to have your measurements taken. But the advantage of knowing your own sizes will make bra shopping easier. Especially if you’re in between sizes you’ll know what to look for.

See my little guide for measuring at home that will show you exactly how to do it yourself.

10. The average bra size in the UK

Every woman and girl is different. Sure we are. Women’s breasts have unique shapes and sizes. No wonder there are over 100 different bra sizes. But what’s the average UK size?

My bra guides

Bras for AAA-C cups & calculator
Bras for D+ cups & calculator
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Check your size in my bra calculator
of visit M&S for advise and size chart

measure tape bra size uk

Marks & Spencer | Find your Perfect Fit
UK | US | CA | IE | ES | FR | AU
select your shop/country