Creative articles about sewing

Making your bra fit – the cups

Hello again

After we’ve looked at the band we will focus on the cups in this post.

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If your wire doesn’t fit your volume

Every pattern will tell you exactly how to measure yourself to get the right cup size. And of course, you should follow that. But what if the wire we chose in step one will not fit the cup size the designer suggests you make? After all there is a reason why we sew our own bras, and most of the time therein lies the issue. We already know that the industry’s standard will not fit us perfectly. The industry however will link a specific wire size to a specific cup size and this scale goes up or down proportionally.

A simple example

Let’s think about this for a minute and I will illustrate the issue with an example. However, every body shape is different and the examples I use, do not necessarily reflect every person that is tall or petite. We are all our own shape and size.

Anyway, let’s think about a tall athletic woman called Nina. Nina has the measurements that put her in a 75C. Now let’s think about a petite woman (Julia) with narrow shoulders but a large chest. She, as well, is supposed to wear a 75C according to her measurements. The industry just assumes that both women will be able to wear the 75C and that may be true but it may also be that the two women will both have their issues with this bra.

Nina has a wider chest than Julia (even though they have the same circumference), but with almost any woman the area where your breast tissue starts relatively to your chest is more or less the same. So, Nina’s breast root will be wider than Julia’s just because her actual torso is wider even though the circumference is the same. When Nina is wearing the 75C the wires might actually poke her because the are too small for her frame. If she sizes up the wires will fit but now she will not fill out her bra. Julia on the other hand might like the 75C wires but her breast tissue might spill out. If Julia sizes up, the new cups will enclose her tissue just fine, but now the wires stand out at the underarm area and she might experience some chaffing.

The power of geometry

Why is this happening? Well, easy, it’s simple geometry. Since the Volume with both ladies is the same but the base differs (wide root, narrow root) the projection will vary as well. While Nina is shallow in her breast and wider, Julia has more projection and is narrower.

Now, you’ll see why we have taken our time with making the band fit us properly, because this will help us discerning if our issues are band or cup related.

After we’ve figured out that our cup volume does not correspond with our wire size, we simply need to make our cup pieces that represent our volume fit into the band that fits our wire. And here’s how we do this. If you are having this issue, I recommend a bra pattern with multiple cup seams. This way you can add or remove directly from the seams without having to insert darts.

I am using the pattern Angies Twin by BWear. The reason for it being the multiple cup seams and the pdf “layering option”. I can simply click on the sizes I need, only print these sizes and blend between the two. I just “activated” the sizes 90D (my wire size) and the 90E (my volume size). If you do not have a layering option I will show you how to adjust that after.

Let’s go!

The brown areas are the ones we do not want to change. The arrows indicate the areas where we can make our alterations. On the left I show you how to blend from a larger wire to a smaller cup volume (so the wire is bigger than the volume would suggest, Nina). On the right you will see the changes you need to make to blend a larger cup into a smaller wire line (Julia).

Since I need the same changes “Julia” would need I adjusted all the pieces to make the bigger cup fit into a smaller wire.

If your pattern does not have layers don’t fret. Just cut out your cup size that corresponds to your volume and sew it up in a stable but cheap material. Now measure the cup seam line and compare it to your fitting band cup seam line. The difference between those two is the amount which you have to adjust. Let’s say your cup seam line is 1.5cm too long; we have three seams and distribute the 1.5cm to each seam, giving you 0.5cm, landing you on 0.25cm on each seam line. Make sure that you remove/add your adjustments in the general cup area – we don’t want to affect the volume.

The left cup is made without the wire adjustments, it’s a Black Beauty Bra cup. I expect the seam line of this cup is going to be too long. The right cup is the one we adjusted to fit our wire line.

I’ve sewn up the cups according to the instructions. The Black Beauty Bra has the top edge finished with fold-over elastic which is why I’m going to leave it as is. Angie finishes the cups with underarm elastic, so I folded the seam-allowance under and topstitched it. The underarm area of both cups is finished with 12mm underarm elastic that finishes in a loop at the top to attach to the G-hooks.

After you’ve made your cup alterations we cut our cups, sew them up according to the instructions and sew them into the fitting band with a simple basting stitch. Remove the wires beforehand or you are sure to break a needle. After inserting the cups, you can put the wires back in and check your fit. If they don’t fit, make the according alterations, sew up your cups and insert these into your fitting band and so forth…

Slowly sew in the cups with a basting stitch. You can do this by hand as well.

This is my finished tester bra. Ready for checking the fit.

The Result

Here you’ll see the result of my cup fittings. As you can see the left cup is much too long and that is easily explained – I have used the Black Beauty Cup that has not been reduced at the seamline to fit my wire yet.

Moreover, you can see that both cups need a wedge taken out at the top toward the center by the same amount, even though they have been designed by two different companies. This is just how my shape is, I have to do this on every bra. It’s a minor fix.


I hope this post will help you getting closer to your perfect fit.

And lastly, I have an added bonus for you. I have wanted labels with washing instructions for a long time. Particularly since I have started making bras for other people. I have had the opportunity to create my own labels with  Nominette.You can create your own using the code NADINE20 and get 20% of your first set of 100 labels.

I’ve sewn in my labels at the very last step before attaching the hook and eyes. Where the eyes will be sewn on you just baste on your label put the eyes on top stitch down and voilà, done!

Happy Sewing


Free sewing tutorial: Making your bra fit – the cups

Difficulty level: Intermediate
Time to Complete: Evening
Used Material: Duoplex, underwires
Used Products:

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