How to measure your bra size: according to experts

You could be doing it wrong without even realising...

by Daisy Hall |
Updated on

Bra sizes, much like women's clothing sizes, appear to be a bit of a myth to most of us but it turns out that there's actually an official science to getting the best bras that fit you properly. Here's how to measure your bra size from the comfort of your own home.

Try the measuring technique for yourself, and next time you go bra-shopping make sure you buy one in your new size. We don't want to make any guarantees… but you’re going to be amazed.

First of all, you need to gather together the following: a soft measuring tape (showing inches), a pen and paper, and some privacy. Optional: all your old bras so you can get rid of them when you realise you've been wearing the wrong size for years. Essential: a whole new drawer full of the best support bras that actually fit you correctly.

How to measure your bra size:

Remove your bra and wrap the tape measure around the very bottom of your boobs. Make sure the tape is parallel to the ground all the way around your chest, and pull it tight enough to stay in place when you move around. Jot down that number – that's your underbust size.

To get your bust size, bend over so your back is parallel to the floor. You might need to use your hands to 'sweep' any excess tissue from your sides and under your armpits to the front. Once that's done, measure around your chest, keeping the tape straight across your breasts at their fullest part. Pull the tape taut – but not tight enough to squish your boobs out of shape. Write down that number - that's your bust size.

How to calculate your bra size:

Now it's time for the maths. Take the first number – your underbust size – and round it up to the nearest whole number. If it's an odd number – 31, 33, 35 and so on – add one inch. This will give you your band size.

To calculate your cup size, subtract your band size from your bust size and round it up to the nearest whole number. So if you're measuring 33.5 inches around your underbust and 38 inches around the fullest part of your boobs, the difference (after rounding up to 34) is four inches.

Now compare your final measurement to the bra size chart below. If your band and bust size is the same, you've got an AA cup. A difference of one inch between both measurements gives you an A cup, and so on. It sounds a bit confusing but just take it slow and you'll be fine.

Bra size chart:

Here's a chart to show the difference in inches between the band size, bust size and what that means for your cup size. You can always get fitted in person by a sales assistant who works in your favourite lingerie brand, too. But, after all, working it out from the comfort of your own home is a lot less effort.

0" – AA

1" – A

2" – B

3" – C

4" – D

5" – DD

6" – E

7" – F

8" – FF

9" – G

10" – GG

11" – H

12" – HH

13" – J

14" – JJ

15" – K

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