Reader P sent her struggle with sister sizes to Help Me Busts 4 Justice. Let’s help her navigate her way to a more comfortable fit…

Help Me Busts 4 Justice!

I just found out my actual size is 28D (I’d been wearing a 34B). I read in one of your articles that 28D is the same as 30C, 32B, and 34A. I’m confused because for a time a few years back I did wear 32B and 34A and neither of them felt good. And I can’t find any affordable stores that actually sell a 28 bra. My boobs are uncomfortable! What do I do?

Hi P,

Thanks for reaching out. While it is true that there are sister sizes that have the same volume as other sizes (eg 34B, 32C, 30D, 28E) – it doesn’t mean that they’ll all fit the same woman. While a 34B and a 28E may technically be the same volume, the way they are structured is very different. This is because on a 34 back the breast is distributed across a wider body, whereas on a 28 the same amount of breast will be protruding forward.

Importantly in this case though, you write that you were a 34B, but that 32B and a 34A were uncomfortable. That’s not surprising as they are not sister sizes to 34B – both 32B and 34A are smaller cup sizes than a 34B. The 28 back sister size of a 34B is actually more like a 28E. That said, as 34B tends to be a ‘catch all’ size for so many women (thanks M&S/Victoria’s Secret!) you may find that a 28E is actually still too small. In that case, size up to a 28F (or higher, if you need to).

You’ll know you’ve found your perfect fit when the band sits horizontal to the floor and flat to the chest in the center, the cups perfectly encapsulate all breast tissue (not sitting on it, or creating pockets of space), and the cups sit smoothly across the breast without digging in, gaping or puckering.

How easy it is to find a 28E largely depends on where you are in the world. If you’re in the UK, you increasingly find 28 backs on the high street in places like Bravissimo – it is well worth making the trip to see them if you can, especially if you’ve never had a decent fitting before. If you’re in the US or elsewhere, if there’s not a specialist boutique in your area you may need to rely on ordering from overseas. Look for companies like Large Cup Lingerie, Brastop or Figleaves who all either offer free international shipping as standard or at least have regular deals.

Good luck – and let me know how you get on!