7 Common Bra Fitting Mistakes and How to Avoid Them

After fifteen years as a professional bra fitter, I have seen the same fitting mistakes repeated countless times. These errors are so common that many women do not even realise they are making them. The good news is that once you know what to look for, correcting these mistakes is straightforward. Here are the seven most frequent bra fitting errors and how to avoid them.

Mistake 1: Wearing a Band That Is Too Loose

This is by far the most common fitting mistake I encounter. Women tend to choose bands that are too large because they feel more comfortable in the fitting room, but a loose band provides inadequate support and shifts throughout the day. The band delivers approximately 80% of a bra's support—when it is too loose, the straps must compensate, leading to shoulder pain and the band riding up at the back.

A properly fitted band should feel snug when fastened on the loosest hook. You should be able to fit two fingers under the band, but no more. Over time, elastic stretches, so starting on the loosest hook gives you room to tighten as needed. If the band rides up at the back or you can pull it more than a few centimetres away from your body, you need a smaller band size.

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Key Takeaway

When you go down in band size, go up in cup size to maintain the same cup volume. For example, if 14C feels loose in the band, try 12D—the cups will hold the same volume with a firmer band.

Mistake 2: Wearing Too Small a Cup

Many women resist going up in cup size due to misconceptions about what cup letters mean. A D cup does not mean you have large breasts—cup size is relative to band size. A 10D contains significantly less volume than a 16D. If your breast tissue spills over the top of the cups, bulges at the sides, or the underwire sits on breast tissue rather than your ribcage, your cups are too small.

Do not be afraid of cup sizes. The goal is comfort and proper containment, not a specific letter. Try different sizes objectively and choose the one that fits best, regardless of what the label says.

Mistake 3: Ignoring the Gore

The gore—the small piece of fabric between the cups—is a critical fitting indicator that many women overlook. In a well-fitting bra, the gore should sit flat against your sternum, fully tacking to the skin. If the gore floats away from your chest, the cups are likely too small. If it digs in painfully, the cups may be too large or the style wrong for your shape.

Some women with close-set breasts find it difficult to achieve a perfect tack with any bra. In these cases, plunge styles with a lower, narrower gore may provide a better fit than full-coverage options.

Mistake 4: Tightening Straps for Support

When a bra does not feel supportive enough, the instinct is to tighten the shoulder straps. However, this is a bandaid solution that creates new problems. Overly tight straps dig into the shoulders, cause pain, and can even lead to nerve damage over time. Straps are meant to hold cups in position, not provide primary support.

If you find yourself constantly tightening straps, the real issue is likely a band that is too loose. Focus on finding a snugger band, and the straps should only need minor adjustment to stay in place without digging in.

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Pro Tip

A simple test: slide the straps off your shoulders. If the bra immediately drops or loses support, the band is too loose. A well-fitted band should hold the bra in place even without the straps.

Mistake 5: Assuming Your Size Never Changes

Your bra size is not a permanent fixture—it changes throughout your life due to weight fluctuations, hormonal changes, pregnancy, breastfeeding, menopause, and even muscle development. Many women continue wearing the same size they were fitted for years or even decades ago, despite significant body changes.

I recommend reassessing your size every 6-12 months, and immediately after any significant body changes. If your current bras no longer feel comfortable or you notice any fit issues, it is time to remeasure rather than struggling along with ill-fitting undergarments.

Mistake 6: Buying the Wrong Style for Your Shape

Not every bra style works for every breast shape, and this has nothing to do with size. Full-coverage bras may gap on women with fuller lower breasts, while plunge styles might not work for close-set breasts. Push-up bras can be uncomfortable for those with very full or soft tissue, while minimisers only work for certain shapes.

Understanding your breast shape helps you select styles more likely to fit well. Are you fuller on top or bottom? Wide-set or close-set? Shallow or projected? These characteristics matter as much as your measurements when choosing a bra style.

Mistake 7: Keeping Bras Too Long

Bras have a lifespan, and wearing them past their prime means wearing unsupportive, ill-fitting undergarments. Elastic fibres break down with wear and washing, bands stretch out, and cups lose their shape. A bra that fit perfectly when new may be doing you no favours after a year of regular wear.

Most bras should be replaced after 6-12 months of regular wear (assuming you rotate between several bras). Signs it is time to replace include: needing to fasten on the tightest hook, straps that will not stay adjusted, cups that have lost their shape, and general loss of support and comfort.

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Important

If you are wearing the same bras you bought several years ago, they are almost certainly past their useful life. Even if they look fine, the elastic will have degraded significantly, providing far less support than when they were new.

Getting It Right

Avoiding these common mistakes is the first step toward bra-fitting confidence. Remember that a well-fitted bra should feel comfortable from the moment you put it on. You should not need to adjust it throughout the day, and you should not feel relieved when you take it off. If any of these ring true for you, it may be time to reassess your current size and style choices.