Trying to work out your bra size? We get it. Finding the right fit can feel confusing, especially when every brand seems to fit a little differently.

That's why we've created our Bra Size Calculator. It's a quick and easy way to estimate your Australian bra size and take some of the guesswork out of shopping for bras online.

Before you get started, take a minute to measure carefully using a soft seamstress' tape measure. The more accurate your measurements, the more accurate your result.

At She Science, we always remind women that your measurements help us find your starting point—they're not always your final size in every bra. Your breast shape, the style of bra, and the brand can all influence what fits best.

Ready? Grab your tape measure and let's find your size.

How to measure (band and bust) 

To calculate your bra size, we'll need two measurements. Your band measurement is taken snugly around your ribcage, directly underneath your bust. Your bust measurement is taken around the fullest part of your bust, keeping the tape measure level all the way around.

For the most accurate result, stand upright and use a soft tape measure while wearing a non-padded bra (ideally one that fits you well).

Common mistakes include measuring too loosely, pulling the tape too tight, or allowing it to sit unevenly around your body. You want the tape sitting firm enough that it will stay in place, but not too firm that its compressing your skin or breast tissue. 

How to use the calculator

Enter your ribcage measurement, in to the Ribcage (band) text input. Please ensure you are toggled to the correct measurement setting - we have both inches and cm's. 
Then do the same with your bust measurement. 

After doing this and hitting 'Calculate my size', your estimated size, based on the measurements you've provided will show. 

What to do with your result 

Now that you have a clearer understanding of what your measurements mean for bra sizing, there are several ways you can use this information. You can click the 'Shop Your Size' button to browse styles available in your starting size online.

Alternatively, you may prefer to visit our Bra Fitting Suites in Hawthorn for a more personalised experience with one of our highly trained Bra Fitters. Don't forget to pre-book your appointment, as we run exclusively by appointment. 

Keep in mind that sizing can vary between brands, so if something doesn’t feel quite right, trying a sister size can often help. You’ll also find 'How She Fits' notes on each style, which may recommend adjusting your size if a particular bra doesn’t fit true to size.

Why getting the right size matters

Any Bra Fitter will tell you, how well your bra functions all comes down to the fit. And the same can be said for comfort too. 

We really want you to experience the benefit of a well fitted bra, so you can live comfortably, confidently and if you're hitting the sports field, that you can perform at your peak. 

F.A.Q 

How do I measure my bra size at home?

Using a soft tape measure, take one measurement around your ribcage directly under your bust and another around the fullest part of your bust. Enter these measurements into our Bra Size Calculator to receive your recommended starting size.

How accurate is a bra size calculator?

A bra size calculator is a great starting point and can be highly accurate when measurements are taken correctly. However, factors like breast shape, bra style and brand sizing can all influence your best fit. A bra size calculator will get you started in the right direction, but won't mean you will definitely be that bra size in every style you try. 

What is my band size vs cup size?

Your band size is the number part of your bra size (for example, 12 in a 12E) and is based on your ribcage measurement. Your cup size is the letter part (E) and reflects your cup size, which is determined by the difference between your bust and band measurements.

What should I do if I am between two sizes?

If your measurements fall between sizes, start with the size recommended by the calculator. We have designed our tool to size up if you are between sizes. This is how we always approach Bra Fittings in person too. 

How often should I re-measure my bra size?

We recommend checking your bra size every 6–12 months, or sooner if you've experienced weight changes, pregnancy, breastfeeding, menopause or changes in exercise habits. Even 3kg weight change can alter your bra size.