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Do You Reckon You Wear The Correct Size Bra?

156 replies

BunnyLover7 · 10/08/2025 17:32

Apparently something like 70% of women wear the wrong size (not sure if that’s UK women). I’ve been for 2 fittings at M & S in the last month or so & hoping the lady I saw today has got it right! Her colleague that I saw before ended up selling me a bra that was actually smaller than the one I’d arrived in ( I didn’t question it until later on as I presumed it was because it was a different style) but it gradually got tighter as the day went on. She’d said that if it turned out that I needed to wear my extender with that bra, which I did, I could then try the next band size up with the same cup size. I ordered 2, meaning I’d spent just over £50 altogether,but unfortunately the same thing happened even with the extender on.
Today, the assistant reckoned I was another band size up & that I fell between 2 cup sizes. I bought 2 different styles of non wired bra in a 42C & so far so good, although obviously I’m allowing for a certain snugness as it’s brand new. Fingers crossed! I was in pain & it even affected my eating so more often than not I went bra less after a certain time of day to get comfortable. Do any of you struggle with bras?

OP posts:
niadainud · 10/08/2025 22:27

After a campaign sustained over several years I finally persuaded my mother out of the 34B bras she had been wearing for about six decades into some 32Ds.

I was perfectly happy with the advice I received in M&S but I was fairly confident of my size to start with. They definitely didn't put me in too big a back size or too small a cup size as I ended up with a 30F.

LillyPJ · 10/08/2025 22:31

dementedpixie · 10/08/2025 18:01

P.s. I measure myself to get a better idea of size

Measure tightly under bust to give the back measurement (without adding extra inches)

Measure around fullest part of bust (not too tightly) and then subtract the under bust measurement from the over bust measurement to get the cup size.

Each additional inch increases the cup size
1 inch - A
2 inches - B
3 inches- C , etc etc

That method doesn't work at all for me. I wear (and am very comfortable in) a 36A. Using your method I'm a 32C. I tried on a 34 B once and it was far too tight around the band. Do different makers use a different sizing system?

LillyPJ · 10/08/2025 22:38

DelilahBucket · 10/08/2025 19:19

Yes I am, because I have measured myself using the Boob or Bust method. I was not however, after an M&S fitting where the band was halfway up my back with no support at all. All the support should be from the band, not the straps. It astounds me how many women insist they are in the correct size when clearly they are not. A 42C means you have 3 inches of breast tissue. A 42 back would generally equate to wearing size 28-30 clothes. It would be highly unlikely to have boobs of 3 inches and be wearing a size 28-30 in clothes. I say generally, it isn't a hard and fast rule, but your clothes size plus 10-14 is usually your back size in a bra.

How does that work? A woman wearing size 12 clothes (UK) is hardly likely to want (or be able to find) a size 22 to 26 bra!

Interested in this thread?

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QwestSprout · 10/08/2025 22:40

I deliberately wear the wrong size, because my autism causes sensory issues and that would include wearing the supposed 'correct' size which I would find too tight. So the cups gape slightly at the top of the sides and a fitter would probably want to reduce the band size. But I'm happy.

beachwalkx · 10/08/2025 22:46

42 is likely too big. I’m an 18 and wear a 34 band which is comfortable
m&S measured me as a 40HH which rode up my back and gave me about 8 boobs, I’m actually a 34KK

BunnyLover7 · 11/08/2025 08:44

quickncncncnc · 10/08/2025 22:24

Oh Bunny, the irony of your thread title and then you have been to M&S, where they measure you incorrectly. There is absolutely no way you are a 42C, not in a million years. Please get a tape measure and share your measurements and we will sort you out!

Do I need to do all of the measurements that they ask for on Boob or Bust?

OP posts:
BusterGonad · 11/08/2025 08:51

LillyPJ · 10/08/2025 22:31

That method doesn't work at all for me. I wear (and am very comfortable in) a 36A. Using your method I'm a 32C. I tried on a 34 B once and it was far too tight around the band. Do different makers use a different sizing system?

I think you've measured incorrectly, you definitely need the band size that you measured at, so a 32, but try different cup sizes. It's very hard to get the correct cup size by measuring over the bust. You need to do the A bra that fits bra size calculator. If you just measure standing up with a bra on you'll get the wrong cup size due to the bra not being the right size, if you do it naked you'll get the wrong cup size unless your very pert. Generally the band will feel too tight if the cups are too small, as the your breasts will push the cups forward taking space from the band and making the band feel tight. I'm guessing your cup size on the bra you're wearing now is way too small and the band is definitely too big.

BusterGonad · 11/08/2025 08:56

LillyPJ · 10/08/2025 22:38

How does that work? A woman wearing size 12 clothes (UK) is hardly likely to want (or be able to find) a size 22 to 26 bra!

A size 10 woman will probably wear a 30 band, size 12= 32, size 14 = 34 etc...

BusterGonad · 11/08/2025 08:56

BunnyLover7 · 11/08/2025 08:44

Do I need to do all of the measurements that they ask for on Boob or Bust?

Yes!

Boredlass · 11/08/2025 08:57

No because I lost 3 stone and I’m still wearing the same bra size. Fella ok though so not bothered

SapphireOpal · 11/08/2025 08:59

LillyPJ · 10/08/2025 22:31

That method doesn't work at all for me. I wear (and am very comfortable in) a 36A. Using your method I'm a 32C. I tried on a 34 B once and it was far too tight around the band. Do different makers use a different sizing system?

To be fair it might have felt too tight round the band because the cup was too small and some of your breast tissue was sitting in the band.

BlondieMuver · 11/08/2025 09:46

Karistyleaftea · 10/08/2025 17:45

Boob and Bust measurement worked well for me.

Yep same. I was wearing 34B.
I'm actually 32DD

HungryAndLazy · 11/08/2025 10:23

By boob or bust I'm a 32GG. I have a strapless bra in this size and its perfect.
I tend to wear 34G or 36F as I prefer a less tight band.

LillyPJ · 11/08/2025 10:51

BusterGonad · 11/08/2025 08:51

I think you've measured incorrectly, you definitely need the band size that you measured at, so a 32, but try different cup sizes. It's very hard to get the correct cup size by measuring over the bust. You need to do the A bra that fits bra size calculator. If you just measure standing up with a bra on you'll get the wrong cup size due to the bra not being the right size, if you do it naked you'll get the wrong cup size unless your very pert. Generally the band will feel too tight if the cups are too small, as the your breasts will push the cups forward taking space from the band and making the band feel tight. I'm guessing your cup size on the bra you're wearing now is way too small and the band is definitely too big.

Edited

No. I've tried a 34 and the band is way too tight so the cup size is irrelevant ( and my boobs are far too insignificant to 'push the cups forward'!) The 36a I wear fits me perfectly so I'm really confused by people telling me I'm 32. I'd barely be able to do the hooks up on the furthest setting, let alone breathe. I can only assume that other bra makers (mine are generally M&S in a wired plunge type) use a different sizing system.

quickncncncnc · 11/08/2025 10:53

LillyPJ · 11/08/2025 10:51

No. I've tried a 34 and the band is way too tight so the cup size is irrelevant ( and my boobs are far too insignificant to 'push the cups forward'!) The 36a I wear fits me perfectly so I'm really confused by people telling me I'm 32. I'd barely be able to do the hooks up on the furthest setting, let alone breathe. I can only assume that other bra makers (mine are generally M&S in a wired plunge type) use a different sizing system.

If the band feels too tight it means your cup size isn’t big enough.

LillyPJ · 11/08/2025 10:53

SapphireOpal · 11/08/2025 08:59

To be fair it might have felt too tight round the band because the cup was too small and some of your breast tissue was sitting in the band.

No, my breast was in the cup. There's not enough of it to spread anywhere else! And I did try going up a cup size but the band was too tight.

LillyPJ · 11/08/2025 10:55

quickncncncnc · 11/08/2025 10:53

If the band feels too tight it means your cup size isn’t big enough.

No! I do the hooks up at the front, then turn it round to get in the cups. If I can barely breathe as soon as I've done the hooks up, it's going to make no difference when I've turned it round and put my boobs in, is it?

LillyPJ · 11/08/2025 10:57

BusterGonad · 11/08/2025 08:56

A size 10 woman will probably wear a 30 band, size 12= 32, size 14 = 34 etc...

So that's clothes size plus 20, not plus 10-14 as the post said.

HundredMilesAnHour · 11/08/2025 10:58

Years ago I went to Rigby & Peller (the original one opposite Harrods) and had a fitting. Not only did I find my correct bra size (and developed a taste for expensive bras) but I learnt so much from the lovely lady who did the fitting.

I’ve tried fittings elsewhere and they weren’t in the same league.

zaxxon · 11/08/2025 11:27

LillyPJ · 11/08/2025 10:53

No, my breast was in the cup. There's not enough of it to spread anywhere else! And I did try going up a cup size but the band was too tight.

Stick with your 36A, that's my advice. I've been told by bra fitters and random internet strangers that I was all kinds of sizes. They were all wrong - they weren't the one who had to wear them!

zaxxon · 11/08/2025 11:29

@niadainud After a campaign sustained over several years I finally persuaded my mother out of the 34B bras she had been wearing for about six decades into some 32Ds.

Why on earth did you do that?

beachwalkx · 11/08/2025 12:11

zaxxon · 11/08/2025 11:29

@niadainud After a campaign sustained over several years I finally persuaded my mother out of the 34B bras she had been wearing for about six decades into some 32Ds.

Why on earth did you do that?

Maybe she had double boobs and a bra band up round her neck
I did it with a gym friend who was complaining about her bra, I could pull it out 6 inches from her back and she had more boob out her bra than in it
she got measured and into a decent sports bra

Youcallisimportant · 11/08/2025 12:14

Yes I do since I had a fitting at Bravissimo. It made an enormous difference to how my boobs looked under my clothing.

BogRollBOGOF · 11/08/2025 13:29

BusterGonad · 11/08/2025 08:56

A size 10 woman will probably wear a 30 band, size 12= 32, size 14 = 34 etc...

That roughly works for me.
Weight lifting has increased my back muscles slightly so I'm slightly over 30" and find 32" less snug as the 30" have become pinchy. Age and children have put me up to about C/D cup depending on cut which is still relatively small.

I lament for my youth wasted in 34A believing I was flat-chested. I was probably 28 and a B/C. Not that 28" backs were avaliable on a budget on the High St around the millennium. Going down backs and up cups has really maximised my modest bust.

I remember arguing with the fitter in M&S at 35wks pg who wanted me to increase the back measurement. I'd gone from "34B" to 34DD and was wanting 34Es for the hospital bag. She was adamantly sticking to some random rule of going up a back and a fixed number of cups that I'd already gone past. I knew it was just the cups growing rapidly not my back, and insisted on buying the 34E... next week I ended up wearing them after yet another growth spurt and ended up having to buy 34F online for the final feeding growth spurt.

LillyPJ · 11/08/2025 13:47

zaxxon · 11/08/2025 11:27

Stick with your 36A, that's my advice. I've been told by bra fitters and random internet strangers that I was all kinds of sizes. They were all wrong - they weren't the one who had to wear them!

Thanks! I'm perfectly happy with my bra size. It fits well, no bulges or gaps, and it's comfortable. I can't understand why people are insisting I'm wearing the wrong size! I'm sure that '70% of women are wearing the wrong size' stuff is just propaganda made up by bra manufacturers wanting to flog more bras.