10 Signs You Are Wearing the Wrong Bra Size

Wearing the wrong bra size is remarkably common, and many women have become so accustomed to discomfort that they no longer recognise it. As a physiotherapist specialising in posture and breast health, I have seen countless patients whose chronic back pain, shoulder tension, and even headaches were directly linked to poorly fitting undergarments. Here are ten signs that your bra may not be the right size for you.

1. The Band Rides Up at the Back

The band of your bra should sit horizontally across your back, parallel to the floor. If the band rides up towards your shoulder blades, it is almost certainly too large. When the band is too loose, it cannot provide proper support, forcing the shoulder straps to bear weight they were never designed to carry. This is one of the most common fit issues and often the easiest to fix—try going down one band size while going up one cup size.

2. Shoulder Straps Dig In or Fall Down

Straps that constantly slip off your shoulders suggest the band is too large or the cup size is wrong. Conversely, straps that dig painfully into your shoulders indicate they are carrying too much weight—a sign that the band is not doing its job. Properly fitted straps should stay in place with minimal tension and leave no lasting marks on your skin.

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Did You Know?

Your shoulder straps should only carry about 10-20% of the support weight. The remaining 80-90% should come from the band. If you have deep grooves in your shoulders at the end of the day, your band is likely too loose.

3. The Gore Does Not Tack

The gore is the small piece of fabric between the cups, also known as the bridge. In a well-fitting bra, this section should sit flat against your sternum, what fitters call "tacking." If the gore floats away from your chest or digs uncomfortably into your breastbone, the cup size is incorrect. A floating gore typically indicates cups that are too small, while a painful gore may mean the cups are too large or the style is wrong for your shape.

4. Spillage Over the Cups

Sometimes called "double boob" or "quad-boob," this occurs when breast tissue spills over the top of the cups, creating an unflattering line visible through clothing. This is a clear sign that the cups are too small. Many women resist going up in cup size due to misconceptions about cup letters, but remember that cup size is relative to band size—a D cup on a size 10 band contains less volume than a D cup on a size 14 band.

5. Gaping Cups

When there is empty space at the top of the cups, or the fabric wrinkles and pulls away from your body, the cups are too large or the style is incompatible with your breast shape. Full-cup bras, for instance, may gap on women with more bottom-full breast tissue. Before sizing down, consider trying different styles—plunge bras, balconettes, or demi-cups may provide a better fit for your natural shape.

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Shape Matters

Not all bra styles work for all breast shapes. If you consistently experience gaping in full-coverage bras, try a balconette or plunge style. If you have wide-set breasts, look for bras with wider-set straps and cups.

6. Underwire Sits on Breast Tissue

The underwire of your bra should completely encircle your breast tissue, sitting on your ribcage rather than on the breast itself. If the wire presses into your breast on the sides or at the centre, the cup is too small. This is not only uncomfortable but can potentially restrict lymphatic drainage and cause irritation over time. The end of the wire should sit at the natural outer edge of your breast, roughly in line with the middle of your armpit.

7. Constant Readjusting Required

A well-fitting bra should feel comfortable and secure from the moment you put it on until you take it off at the end of the day. If you find yourself constantly pulling up straps, tugging down the band, or adjusting the position of your breasts within the cups, something is wrong. You should be able to move through your day without giving your bra a second thought.

8. Red Marks and Indentations

While some light marks from elastic are normal, deep red indentations, lasting marks, or skin irritation indicate a fit problem. These marks most commonly appear under the bust from an overly tight band, on the shoulders from straps bearing too much weight, or around the cups from wires that do not match your shape. Persistent marks can lead to skin breakdown and should not be ignored.

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Important

If you notice persistent skin irritation, rashes, or broken skin from your bra, stop wearing that bra immediately and have your size professionally assessed. Continued wear can lead to more serious skin conditions.

9. Back Fat Bulging

While no bra can completely eliminate the natural fold of skin that occurs when fabric meets body, excessive bulging around the band at the back suggests the band is too small or positioned incorrectly. A properly fitted band should sit level and create a smooth line. If your band seems to cut into your back, try a larger band size or look for bras with wider, more comfortable bands.

10. Discomfort You Have Learned to Ignore

Perhaps the most insidious sign of a poorly fitting bra is discomfort that you have normalised. Many women believe that bras are inherently uncomfortable, but this is simply not true. A properly fitted bra should feel supportive without being restrictive. You should not feel relieved when you take it off at the end of the day. If you do, it is time to reassess your size and style.

What to Do Next

If you recognise any of these signs, do not despair. The first step is to accurately measure yourself using a reliable method. Consider visiting a professional fitter for a comprehensive assessment, particularly if you have been wearing the same size for many years. Our bodies change over time, and what fit perfectly five years ago may no longer be appropriate today.

Remember, finding the right bra is not just about comfort—it is about supporting your posture, preventing pain, and feeling confident in your body. Take the time to find what works for you.