Breasts come in all different shapes and sizes, regardless of whether you grew them in puberty or more recently. Just like there is no ‘standard’ breast shape for cis women, there is no standard for trans women either.
That said, there are some general anatomical differences between cis and trans women that can effect the shape of the breast and fit of the bra. Generally, trans women will have broader shoulders and a wider rib-cage, leading to different breast-to-band ratios (the metric used to determine cup size). The wider rib cage also means that trans breasts are generally farther apart, with more space in between, than cis women’s breasts.
Trans breast shape can also be different, with most trans women stoping at Tanner Stage 4, while most cis-women get closer to Stage 5. This matters less than overall rib cage size for Bra fit, however, as the breast will generally deform to fit the bra cup.
The last factor for most trans women is breast size. Without breast augmentation, most trans women will see their growth stop somewhere around an A or B cup. Combined with the larger chest diameter, this can make finding an appropriately small cupped bra hard at the larger band sizes, since cis women tend to have proportionally larger breast to band ratios.
How to accurately measure your bra size
I see a lot of confusion out there on how to find your bra size. Since most trans women (especially early on) don’t want to get fitted at a store, it can be a really confusing process, and the bra industry largely assumes you already know your measurements.
Bra sizing is determined based on two measurements, the band and the bust. Band is measured around your chest just under where the breast starts to protrude outwards. Bust is measured around your chest at the nipples (usually the widest part). For both measurements, you’ll want to round up, rather than down (you’ll see why later) to the nearest whole number. Band sizes are generally spaced by 2” increments, e.g. 34”, 36” etc. Again, you’ll want to round up.
Cup size is determined by subtracting the bust size from the band size. The difference between the two is the cup size; 0 or less is an AA/AAA, 1” is an A, 2” is a B cup, etc. BUT, and this is what most people miss, you have to add 4” to the band size in order to get an accurate bra size. So a 36A bra has a true band measurement of 32” with a bust measurement of 37”.
Finding a bra that fits
The problem for trans women is that the increased size of the rib-cage will throw off the cup volume measurement, because the chest itself takes up more space than is assumed in the standard bra sizing tables. So while your measurements might show you are a 40B (36” band and 42” bust) your boobs will be swimming in your bra cups, and you might actually find a 42A fits you better.
That said, there are a couple of companies that specialize in bras for small-cupped women, which tend to fit the shape of trans bodies better. Here are a few of my favorites. (Note I’m currently a 36AA, so small cup size is harder to find than band size for me. Many of you ladies will have the opposite problem of struggling to find a larger band size.)
- Lulalu: This is my go to brand for bras. They have a great selection of small cup bras, both wired and wire free, starting in AAA cups. The band sizes are definitely on the smaller end, but the underwires are generally flatter and farther apart and fit the wider chest of trans women better. The matching panties are great too 😉.
- Pepper: Also a great choice, and I own a few of their different styles. Bra cups tend to run a bit bigger, starting at AA cups up through B. Band sizes are also a bit bigger, and you can find a 40AA in some styles.
- Little Women: A British company that caters to small chested women. Lots of great styles, but sometimes hard to find in stock.
Things to look for when bra shopping
Part of the fun of having breasts is wearing all different types of bras. As you build your collection, there are generally some things to think about, especially as you’re trying to find the perfect fit.
- Look for wire-free. Generally, underwires in bras designed for cis women are going to be less comfortable for most trans women. This is because the underwire is designed for a smaller rib-cage, and you’ll find it digs into the outside of your breast in an uncomfortable way. Wire-free avoids this problem by ditching the wire entirely, with a soft yet firm band of fabric underneath the cup supporting the breast. This will fit your chest shape much more naturally and be a whole lot more comfortable.
- When in doubt, go bigger band and smaller cup. As mentioned above, if you struggle with the sizing of standard bras, you can move up in band size and down in cup size to get a better fit. The breast volume on a 34B and a 36A is exactly the same, but the ratio of band size to bust size is different. This tends to provide a better fit on the trans female rib cage.
- Pullover styles are your friend. As sexy as a underwire Demi cup might look, for everyday you may find a pullover style bra more comfortable, as the band will stretch and size won’t be as important. There are plenty of pull overs that are sexy, lacy, and all the things you might look for in a bra, while also being a lot more comfortable and forgiving of trans body shapes.
I’d love to hear what bra brands and styles you find work best for you in the comments!