How to Make This Bra + the Perfect Bra Cup for Any Size 🍈

There is something deeply satisfying about wearing a bra that actually fits. Not one that digs into your shoulders, rides up your back, or leaves you readjusting every hour. A bra that was built for your body, in a fabric you chose, with a cup that sits exactly where it should. That is what sewing your own bra can give you — and once you understand how the cup construction works, you can adapt it for virtually any size.

This guide walks you through the full process: choosing your materials, drafting or adjusting your cup, assembling the bra, and finishing it so it looks and feels like something you actually want to wear. Whether you are a 32A or a 42G, the principles here apply to you.

Why Sewing Your Own Bra Is Worth It

The lingerie industry has improved in recent decades, but there are still massive gaps in what is widely available. Extended sizes can be hard to find in physical stores. Underwire shapes are often standardized to fit a narrow range of breast shapes. And if you have asymmetrical sizing, a very projected shape, or a high or low root, finding a ready-to-wear bra that genuinely works can feel like a part-time job.

Sewing your own bra solves all of that. You can choose the exact wire size and shape, draft a cup that matches your actual projection and width, and pick fabrics that feel good against your skin. The upfront learning curve is real, but after your first successful bra, you will wonder why you waited so long.

Bra sewing also gives you access to the world of bra-specific materials — powernet, stretch lace, bra foam, channeling, and ring-and-slider hardware — that simply does not exist in most mainstream sewing conversations. Once you start sourcing these materials, an entirely new world of construction possibilities opens up.

What You Will Need

Before you start cutting fabric, gather your supplies. Skimping on materials is one of the most common reasons a first bra does not come out well. Bra sewing is an investment in the right notions, and those notions make an enormous difference.

Fabrics and materials:

Bra fabric is not interchangeable with regular stretch fabric. You need specific materials designed for lingerie construction. For the cup, stretch lace or bra foam (sometimes called molded cup foam or plunge foam) works beautifully depending on whether you want a padded or unpadded result. For the band and wings, powernet is the standard choice — it has a firm two-way stretch that holds everything in place without feeling rigid. You will also want a soft knit or stretch fabric for the lining, especially if you are using lace on the cup exterior.

Notions and hardware:

This is where the specifics really matter. You will need underwires in the correct size for your frame, not just your cup volume. Underwire channeling, also called casing, is a narrow tube of fabric that encases the wire and keeps it in place. Bra elastic comes in several varieties: picot elastic (with a decorative looped edge) for the neckline and leg openings, plush-backed elastic for the band where it sits against the skin, and strap elastic for the shoulder straps. You will also need a bra hook-and-eye closure for the back, and ring-and-slider hardware for adjustable straps.

A sharp ballpoint needle sized for stretch fabrics is essential, as is a good zigzag stitch or a serger if you have one. A walking foot helps keep layers from shifting.

Notions sourcing tip: Companies like Emerald Eline, Merckwaerdigh, Sew Sassy, and Bra Makers Supply specialize in these materials. Searching specifically for “bra making supplies” will get you much further than your local fabric shop.

Understanding Cup Construction: The Foundation of a Perfect Fit

The cup is the most technically interesting part of a bra, and it is also where fit is made or broken. Before you ever cut a piece of fabric, you need to understand a few concepts.

Cup projection vs. cup width: These two measurements describe the shape of the breast and do not always correspond to the same letter size. A breast with high projection sits forward from the chest and needs a deeper cup. A breast with wide root spreads laterally across the chest and needs a wider underwire. Commercial bras often get one right and miss the other entirely.

The underwire is the frame: The underwire defines the base of the cup. It needs to sit flat against your ribcage on all sides without lifting or poking. If the wire is too narrow, it will sit on breast tissue. If it is too wide, the side of the wire will dig into your armpit. Correct wire sizing is arguably more important than cup volume when it comes to comfort.

Seam placement determines shape: A two-part cup (with a horizontal or diagonal seam) gives different shaping than a three-part cup (with both a vertical and horizontal seam). The seam placement controls where the fullness of the cup is directed. A princess-seam or T-seam cup tends to work beautifully for projected shapes. A simple half-cup seam suits shallower or more widely-set breasts.

Ease is not your friend in bra cups: Unlike garment sewing where you add ease for comfort, bra cups are drafted with very little ease. The cup fabric should hold the breast in place, not balloon around it. This is a mental shift worth making early.

Taking Your Measurements for Bra Making

Bra making uses different measurements than conventional sizing. You will need:

Your band measurement, taken snugly around your ribcage directly under your bust. This number will correspond to your bra band size — if it measures 32 inches, you are a 32 band. Some patterns add 4 or 5 inches to this number (an older standard), but modern bra making skips the addition and uses the actual measurement.

Your bust measurement, taken at the fullest point of your breast with a soft tape, held parallel to the floor, not pulled tight but sitting gently against the skin.

Your underwire size, which is related to your breast width. This one is tricky to self-measure, but a good starting point is to measure across the base of one breast from one side to the other while leaning forward at a 90-degree angle. This gives you a rough wire width to look for. Underwires are typically labeled by number (28, 30, 32…) and you may find your wire size is different from your band size.

Once you have your bust measurement and band measurement, the difference between the two determines your cup volume. Every inch of difference roughly corresponds to one cup size — 1 inch is an A, 2 inches is a B, 3 inches is a C, and so on.

Choosing or Adapting Your Pattern

For beginners, starting with a commercial bra pattern is strongly recommended. Designing a bra from scratch involves significant pattern drafting skill, and even experienced sewists often use a tested commercial base. Brands like Cloth Habit (the Harriet Bra), Orange Lingerie (the Watson Bra), and Porcelynne offer patterns that are well-drafted and come in a range of sizes.

Most commercial bra patterns offer a size range and include grading instructions. Here is how to adapt a cup for your specific shape:

For high projection: You will need to add volume to the center and tip of the cup. This is done through a technique called a cup pivot — you slash the cup pattern piece from the tip toward the seam allowance and spread it open, adding a wedge of extra volume. This is similar to adding a full bust adjustment in garment sewing.

For shallow projection: The opposite applies. You take a tuck in the cup to reduce depth at the apex, moving the fullness outward.

For wide-set breasts: Extend the underwire channel outward at the side seam and widen the cup at the outer edge.

For close-set breasts: Reduce the cup at the inner edge, and consider choosing a cup style with less center gore width.

For asymmetrical sizing: Cut separate cups for each side using the appropriate adjusted pattern piece for each breast. This is one of the biggest advantages of sewing your own bra and something no commercial product can offer.

Cutting Your Fabric

Once your pattern is adjusted and tested (more on that below), cut your fabric carefully. With lace or sheer fabrics, pay attention to which direction the pattern is placed so the design lines up symmetrically. With foam cups, use a rotary cutter and a sharp blade for the cleanest edge.

Transfer all pattern markings — notches, apex point, grain lines — to your fabric pieces. The apex marking is particularly important because it tells you where the fullest point of the cup should sit, which in turn guides your underwire placement.

Sewing a Fabric Mock-Up First

This step is non-negotiable for any bra that requires a good fit. Bra foam and stretch lace are not cheap, and sewing a mock-up in inexpensive powernet or swimwear fabric before cutting into your real materials saves time, money, and frustration.

Sew the cup pieces together using your real underwire, and try it on with the elastic and hardware temporarily basted in place. What you are checking:

Is the underwire sitting flat against the ribcage all the way around, including at the center gore? Is the cup fabric smooth over the breast without wrinkling horizontally (which means the cup is too shallow) or pulling vertically (which means the cup is too projected at the base)? Is the apex of the cup sitting at the fullest point of your breast? Is the band sitting level around your body?

Make your adjustments, re-sew the mock-up if needed, and only when you are happy with the fit should you move on to your real fabric.

Assembling the Bra: Step by Step

With a good mock-up behind you, the real construction can begin. Here is the sequence that works best for most two-part cup bra patterns.

Start by sewing the cup seam. Pin the upper and lower cup pieces right sides together, matching the notches, and stitch with a narrow zigzag. If you are using foam, sew with the foam side down against the feed dogs. Trim the seam allowance and press it (or finger press it if using stretch lace).

Next, construct the underwire channel. Fold the channeling over the base of the cup and stitch it in place using a zigzag stitch, leaving one end open for inserting the wire later. The channel should be just wide enough that the wire slides in without excess space — a snug fit prevents the wire from migrating over time.

Attach the cup to the band. With right sides together, pin the cup to the band, easing the cup edge to fit the band’s top edge. Stitch carefully, maintaining tension so the fabric does not stretch or pucker. This seam carries a lot of stress in wear, so reinforce it with a second line of stitching or a serged edge.

Apply the picot elastic to the top edge of the cup and the neckline. Stretch the elastic gently as you sew so it lies flat when released. The picot edge should face outward, creating that delicate scalloped effect along the edge.

Stitch the side seams and attach the back wings, then apply the band elastic and back closure. The hook-and-eye tape is sewn to the back edges, with the hooks on the right back piece and the eyes on the left. The elastic on the lower band edge should be applied with the plush side facing inward, toward the body.

Finally, insert the underwire into the channel and stitch the end of the channel closed. The wire should sit snugly in its channel with no wiggle room. Then attach the shoulder straps using the ring-and-slider hardware.

Getting the Cup Right for Larger Sizes

Larger cup sizes (typically D and above) come with specific construction challenges that smaller cups do not. The weight of the breast means every element needs to be more robust.

Use firmer powernet in the band. A longer band with stronger powernet provides the lift and support that does the actual work in a fuller bust bra. The straps are not meant to bear the primary load — the band should.

Consider a three-part cup. The additional seam in a three-part cup creates more controlled shaping and can better accommodate high or low projection alongside significant cup volume.

Choose a wider underwire. Wider wires distribute weight more effectively and prevent the wire from digging in at the sides. Make sure the wire length is also proportionate — a wire that is too short will be uncomfortable under the arm.

Add a cradle or sling. Some fuller-bust patterns include an internal cradle — a horizontal strap of firm fabric inside the cup that creates an inner support structure. This is particularly effective for sizes G and above.

Caring for Your Handmade Bra

Bra elastic and bra fabrics are delicate and will degrade much faster if machine washed or dried on heat. Hand washing in cool water with a gentle lingerie wash, then laying flat or hanging to dry, will dramatically extend the life of your handmade bra. Avoid wringing or twisting the cup foam if you used it, as this distorts the shape.

Troubleshooting Common Cup Problems

Horizontal wrinkles across the cup: The cup is too deep for your projection. Reduce the cup depth by taking a horizontal tuck at the apex.

The cup fabric pulls away at the top: The cup is not deep enough, or the upper cup piece is too small. Add a pivot adjustment to deepen the cup.

The underwire pokes at the center: The center gore is too wide or the wire is too long. Try a shorter wire or reduce the width of the center gore pattern piece.

The cup falls forward: The straps are too short or the cup is not anchored well enough at the band. Check your cup-to-band seam and lengthen the strap.

The band rides up at the back: The band is too long or the back elastic is not firm enough. Take in the side seams or try a stiffer powernet.

The Joy of a Bra That Actually Fits

There is a particular pleasure in wearing something you made with your hands — and that pleasure is doubled when it fits perfectly. A well-constructed handmade bra can outperform almost anything you will find at retail, because it was built around your actual body rather than a standardized set of measurements.

Once you have completed your first bra and worked out the adjustments for your shape, subsequent bras become much faster. You can batch-cut your adjusted pattern in multiple fabrics, sew a set of matching bras and underwear, or experiment with different cup styles using the same tested base.

The perfect bra cup is not a myth, and it is not only available to people who fall within a narrow commercial size range. It is something you can draft, adjust, sew, and wear — starting with the instructions in this post and a willingness to make a mock-up or two before committing to your real fabric.

Pick up your powernet, thread your needle, and make yourself something that fits exactly right.