How to Find the Perfect Bra Size

It’s been a long time since some of us have gone to an actual retail store with sales professionals to help us out. This means that it might have been a while since you’ve been measured for the perfect bra size.

If you’re due for a brand new bra but you need new measurements, we’ve got great news for you—you can find the perfect bra size at home by yourself. You simply need a flexible measuring tape like you’d use in sewing and garment construction (check your sewing box) and a lightly padded bra.

This handy little guide will help you take your measurements and find your perfect bra size. But before you start taking your measurements we should note that you want to make sure you’re wearing a non or lightly-padded bra before you start measuring yourself. It’s just you and the tape measure, no one else will know the true numbers 😉

pink bra

Royce Lingerie Maisie Bra

Step 1: Measure Your Band Size

The band of your bra sits just under below your breasts and clips in the back—while it seems like this might be obvious, it’s important to point out because that’s where you have to measure.

Take your tape measure and wrap it around your body, front and back, and tuck it right under where your bra is sitting. You want it to be comfortable and not too smug, and you’ll need to capture the nearest even number.  

Step 2: Measure Your Bust Size

Your bust is the fullest part of your chest. This is where making sure you don’t have an uber-padded bra when measuring otherwise you’ll come up with measurements that are too large.

That said, you’ll likely want to take your measurements with a bra on simply to hold your breasts in the right place. Otherwise, you might struggle to get the job done! 

Step 3: Find Your Cup Size

With your band and bust size figured out, finding your cup size is easy. You simply need to subtract your band number from your bust number. For example, if your bust is 36 inches and your band is 35, the difference between the two is one inch.

It’s the difference between the bust and band that determines your cup size. If both are the same size, your bra cups should be AA. However, if there is a one-inch difference, your bra cups should be an A. Each additional inch raises your cup size accordingly. 

For example: 

Bust-to-band Difference

Corresponding Cup Size

Same size














black bra

Royce Lingerie Georgia Bra

Step 4: Put It All Together

When you have all of your measurements done, you’re ready to put everything together. The bra size you’re looking for is your band size plus your cup size. For example, if you have a 36-inch band and your cup size is C, then you’re looking for a 36C. 

The truth is, these measurement techniques are general rules but the only true test of the perfect bra size is whether or not it fits correctly. Bras that fit right should have:

  • Cups that properly cover your breasts
  • Straps that don’t dig into your shoulders or fall off
  • A band that sits comfortably around you on any hook (though am for the smallest one)
  • Underwire that sits and stays comfortably under your breasts

If you are buying a bra online, make sure to double-check the sizing guide provided by the manufacturer. While many use standard bra sizing, not all of them do. It’s best to double-check their measurements before hitting that check-out button.

Final Tip for the Perfect Bra Size

Measuring to find your perfect bra size once isn’t enough. Regardless of your age, the size of your breasts is bound to change so it’s important to not cling too much to any particular size.

You’ll want to make sure that you repeat these steps on a semi-regular basis. Chances are your bra size won’t change week-to-week or month-to-month. But it doesn’t hurt to check in every once in a while to make sure your measurements are correct.

This is especially the case if you feel a change in the current bra you’re wearing. If the straps start to fall often or your breasts don’t fit right in the cups, it might be time to change your size (or simply update your bra).

Looking for a brand new bra? We’ve got you covered. Check out our lingerie section for your new favourite!