It’s one of the best-kept secrets in fashion: the vast majority of women go through their entire lives never wearing a bra that truly fits. Studies suggest that figure is as high as 85%. The consequences go beyond minor discomfort — an ill-fitting bra can cause back pain, poor posture, shoulder grooves, and a silhouette that’s less than flattering.

At The Bra Factory, we believe every woman deserves to feel supported — literally and figuratively. That’s why we’ve put together the most comprehensive fitting guide you’ll find, all in one place.

Step 1: Measure Your Band Size

Using a soft measuring tape, measure snugly around your ribcage, just beneath your bust. Keep the tape parallel to the floor. If the number is even, that’s your band size. If it’s odd, round up to the next even number. For example, a 33-inch measurement becomes a size 34 band.

Step 2: Measure Your Bust

Now measure around the fullest part of your chest — across the nipple line — keeping the tape relaxed (not tight). This gives you your bust measurement.

Step 3: Calculate Your Cup Size

Subtract your band measurement from your bust measurement. Each inch of difference corresponds to a cup size: 1 inch = A, 2 inches = B, 3 inches = C, 4 inches = D, and so on. So a 34-inch band with a 37-inch bust = a 34C.

Understanding Sister Sizes

Here’s a game-changer most women never learn: sister sizes. If a 34C doesn’t feel right, the cup volume stays the same when you go to a 36B (bigger band, smaller cup letter) or a 32D (smaller band, bigger cup letter). This flexibility means your perfect fit is closer than you think.

• Always measure yourself at the end of the day when your body is at its most natural state.
• Measure without a bra on, or wearing a non-padded bralette for the most accurate reading.
• A properly fitting bra should sit flat against your sternum — no gaps, no digging.
• The centre panel (the gore) should rest flush against your chest, not float away from it.
• Straps should be snug but not painful — you should be able to slip two fingers underneath.
• If you’re overflowing the cups, size up. If there’s wrinkling fabric, size down.

When to Get Remeasured

Your size isn’t forever. Weight fluctuations, hormonal changes, pregnancy, and even ageing can shift your measurements significantly. We recommend getting re-fitted at least once a year — and The Bra Factory offers complimentary fitting consultations in-store and online. Because you deserve to feel perfectly held every single day.