How to Choose the Right Bra Size

Choosing the right bra size is one of the most important steps in building a comfortable, flattering lingerie wardrobe. Wearing the correct bra size improves support, enhances shape and prevents common issues like back pain, strap digging and gaping cups. If you’re shopping for bras online in Australia, knowing how to measure your bra size properly makes all the difference and using this bra size guide will help you find the right fit.

Step 1: Measure Your Band Size

Using a soft tape measure, wrap it firmly around your ribcage directly under your bust. Keep the tape level and snug but not tight. This measurement in centimetres determines your band size. A well-fitting band should sit straight across your back and feel secure on the loosest hook.

Step 2: Measure Your Bust

Next, it is best to keep your bra on for this step. Measure around the fullest part of your bust (usually across your nipples), while keeping the tape comfortably relaxed. Subtract your band measurement from this number to calculate your cup size. The difference between these measurements determines whether you are an A, B, C, D or fuller cup size.

Step 3: Cup Size

Once you have your measurements for step 1 and 2, you can calculate your cup size. Calculate by subtracting the band size from the fullest bust measurement. Match this difference to a letter:
1 inch (or 2.5 cm): A

2 inches (or 5 cm): B

3 inches (or 7.5 cm): C

4 inches (or 10.0cm): D and so on

You can also click here to confirm your bra and cup size after steps 1 and 2

Signs You’re Wearing the Wrong Bra Size

Many women in Australia wear the wrong bra size without realising it. Common signs include straps slipping, cups overflowing, underwires digging in or the band riding up at the back. If your bra feels uncomfortable after a few hours, it’s time to reassess your measurements using this bra size guide .

Cup size (Australia)
To find your cup size, measure around the fullest part of your bust, again it’s best to keep your bra on for this. See arrow around breasts. You should always round up this measurement to get your correct cup size, for instance 83.8 cm will become 84 cm. There are enormous differences in cup size notation between manufacturers above D. So it is best to check the manufacturer’s measurements in the Size Guide on each product page to ensure the correct fit.

Click this external link Bra sizing guide calculator to convert from various international sizes or to calculate your bra size from measurements.

Choosing the Right Style for Your Shape

Beyond the bra size guide, selecting the right style matters. A balconette bra enhances lift, a plunge bra works under low-cut outfits, and a full coverage bra offers maximum support for larger busts. Matching your bra size with the correct style ensures both comfort and confidence.

At Mary’s Lingerie Online, we offer a wide range of supportive bras, lace bras, plus size bras and matching bra and panty sets designed to suit Australian women. Use this bra fitting guide to find your perfect fit and shop with confidence knowing you’re choosing lingerie that feels as beautiful as it looks.