How do Bra Sizes Work? Letters, Numbers and Cup Sizes Explained

After discovering my actual bra size I though it was time to start a bra series on my YouTube channel. The first question I get is how do bra sizes work.

I’ve stepped away from the Victoria’s Secret measuring methodology, no longer adding 4-5 inches to the band and measuring across the chest on a random diagonal angle that has nothing to do with the actual bust. I suggest you check out my bra fitting experience video if you have no idea what I’m talking about.

I also briefly cover inconsistencies across brands and different countries. Just because you wear a 32G in Natori, it does not mean you wear a 32G in Freya. You would be surprised at how many sales associates at specialty bra shops in Montreal didn’t know this. I couldn’t believe, a novice like myself, was educating them on that matter.

How do Bra Sizes Work?

  • the number indicates the band measurement in cm or inches, depending on the country, it goes up in increments of 2 inches or 5cm
  • the letter signifies the difference in cup and band measurement, in other words, there is no need to gasp at DD+ measurement (as this is actually very common)
  • the band should be snug because it holds 80% of your breast weight and works to anchor your bust and provides lift
  • your bra should stay put, even when you straps aren’t on
  • if your straps have a two-finger tension, they should never slip off your shoulders

Letters, Numbers and Cup Sizes Explained

UK bra sizes

5” difference between band and cup = DD
6” difference between band and cup = E
7” difference between band and cup = F
8” difference between band and cup = FF
9” difference between band and cup = G
10” difference between band and cup = GG
11” difference between band and cup = H
12” difference between band and cup = HH
13” difference between band and cup = J
14” difference between band and cup = JJ
15″ difference between band and cup = K

Notice how UK sizing doesn’t do double E and it skips I.

US bra sizes (sort of)

5” difference between band and cup = DD/E
6” difference between band and cup = DDD/F
7” difference between band and cup = G
8” difference between band and cup = H
9” difference between band and cup = I
10” difference between band and cup = J
11” difference between band and cup = K
12” difference between band and cup = L
13” difference between band and cup = M
14” difference between band and cup = N
15″ difference between band and cup = O

Notice how US sizing differs because it stops using double letters at D, it doesn’t skip I, and more confusingly it does not always begin this way in the 5″ plus range. Good luck with that, I’ve had fun trying to figure out why.

EU bra sizes

5” difference between band and cup = E
6” difference between band and cup = F
7” difference between band and cup = G
8” difference between band and cup = H
9” difference between band and cup = J
10” difference between band and cup = K
11” difference between band and cup = L
12” difference between band and cup = M
13” difference between band and cup = N
14” difference between band and cup = O
15″ difference between band and cup = P

The EU version is similar to the US, except they don’t play around at the beginning of the DD+ range. Please note this does not include Polish or FR sizing, furthermore, brands like Empreinte work differently.

Different methods to getting your bra measurement

  • Measure your rib cage, underneath the bust and then round the number up to an even number if the measurement is odd
  • Measure your overbust, the measuring tape should lay firmly across the fullest part of your breast without pressing down on your tissue and should be paralell to the floor.
  • These steps give you a STARTING point to finding the right bra

Here’s an example of how you would get a measurement from these variables.

31” underbust with 37” overbust (round up to 32″)
37” – 32” makes a 5” inch difference

The measurements indicate a 32DD.

Some things to consider

In theory, the volume of a 30F should always be the same from one bra to another, but that’s simply not the case. Bra size is not standardized across the board.

Bra sizes are not indicative of how wide or narrow the wires are, nor the height or debt of a cup on any given bra. Cup height makes a huge difference for women who are short, have short torsos and/or for women who have short rooted breasts. Yes, root height is a thing. There are even more examples of breast shape which influence fit.

Band accuracy is hard to determine since different companies and countries have different standards. Fabrics have different stretch ability and thickness, all of which influences the fit of the band and cup. Furthermore, some brands use band measurement to denote the furthest it can stretch, others vary.

Fit, to a certain degree is subjective. For instance, someone with a lot of soft tissue around their rib cage might find it more comfortable to size down in band size while someone who has a boney-rib cage will find they prefer a stretchier band because there’s not enough cushion to protect from the wire pressing against the body uncomfortably. This is where people adopt sister sizes, for example, they may choose to wear either 30G or 32F depending on the bra in question.

That’s why measuring is just a starting point. Pick up multiple sizes from different brands and in varied styles to find what works best for you. Viola, you’ve been converted to bravangelism!

How do you know if your bra fits correctly? I’ll let you know in my next video!

xx

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