Working out your bra size feels like an exercise in confusion at the best of times, doesn't it?! And after surgery it can feel even more intimidating. 

Bra sizes are a complicated science - you may have found you're seemingly a C cup in one brand and a D in another.... confusing, right? 

But never fear, you don't need an advanced degree in engineering to deduce your size.

Let's talk first about working out your bra size the traditional way.

Finding your size

Bra sizes are calculated based on your band size and cup size, both of which are determined using measurements are your rib cage and bust respectively. 

Here are our tips on how to measure for your bra size:

• Start off wearing a non-padded bra
• Stand naturally 
• Using a measuring tape, measure your "underbust" (your rib cage, just below your boobs). Stand in front of a mirror so that you're sure the measuring tape is straight and snug around your rib cage. Take the measurement in inches and round it up to the nearest whole number - this is the number part of your bra size (e.g. 32B)
• Next, measure your "overbust". This time, ensure the measuring tape is snug and straight around the fullest part of your bust. (If you wear a breast form, measure your natural breast)
• Here's where we get a little mathematical. To calculate your cup size, subtract your band measurement from your cup measurement. If there are 2 inches difference between the band and cup measurements the you're looking for a B cup, 3 inches difference and you're a C cup, 4 inches difference and you're a D cup and so on. For example, if your underband measurement was 32 inches and your overbust measurement was 34 inches, you are a 32B. (34 minus 32 = 2 i.e. a B cup)

Sister sizes

Still with us?

Here's where things get a little more complicated... Have you ever heard of sister sizes?

80% of women are wearing the wrong size bra. Everyone’s seen a statistic a bit like that, right?

Sister sizes can be the secret to a perfect fit! Often  you're not far off finding your perfect fit - you might just need a slightly smaller or larger band... and that's where sister sizes come in.

So what are “sister sizes”? Sister sizes are groups of equivalent bra sizes by cup volume. For example, a 34C bra has the same size cups as bras that are 30E, 32D, 36B and 38A. We know. It blew our minds too!

If you’re anything like us, you’ve been measured some time ago and learned that you’re roughly a certain size and that’s what you’ve been wearing ever since. It had never even occurred to us that someone who was a B cup could also be a D!

Knowing about sister sizes can be helpful in finding the perfect fit. For example, if the cups fit well, but you're finding a band size is too loose, you may wish to try a smaller band size and this will mean a larger cup size to maintain the same cup volume. So if you've been fitted and told you're a 36C and your find that the cup provides good coverage but the overall fit is a little tight on your back, you might want to try a 38B. this would give you a looser fit with the same cup volume as the 36C.  It's like magic!

Here's a handy table to help you work out your sister sizes. Find your size and then look at the sizes directly to the left and right - those are your sister sizes!

International sizes

It's worth noting that there are some differences in sizing between countries.

Here are some comparison charts to help you to identify you UK size if you are ordering from outside the country:

International bra sizes comparison - bands  

International bra sizes comparison - cups 

If you’re ordering from outside the UK and you’re not sure about your size, please drop us an e-mail at info@valiantlingerie.com