How to Measure Your Bra Size, Plus a Chart & Calculator

If you're reading this, you probably know as well as any other woman that finding your bra size isn't as clear-cut as you once thought. Your bra size has likely changed throughout your life, which can happen for a number of reasons including fluctuating weight and having children.

Helping other women learn how to measure bra size is part of what got us here. By learning the different shapes, sizes, and measurements of millions of women, we created bras with unmatched comfort and support.

In this article, we're going to break down how to measure your bra size in three easy steps so that the next time you go bra shopping, you'll have a better idea of what to look for when trying to find your best-fitting bra.

How to Measure Bra Size in 3 Steps

There's much more to measuring your bra size than just grabbing a measuring tape and marking down a band size (if only it were that simple!). In the next three steps, we'll go into measuring your band size, then your bust size, and lastly, your cup size.

Determining the correct – and most current – measurements for your band, bust, and cup will make it SO much easier for you to find bras that fit right, and fit you, no matter where you get your bras. Plus, with those measurements, you'll finally get confirmation to toss out or donate those bras in your drawer that you've been keeping just to keep.

Step 1: Find Your Band Size

Make sure to wear a lightly-lined or unpadded bra before measuring your band size. Take out a measuring tape and wrap it snugly across your back, keeping it parallel to the ground, and measure directly under your bust. Round down to the nearest even number and note your band size.

Step 2: Measure Your Bust Size

Keep the measuring tape around your back at band level and measure across the fullest part of your chest, making sure to hold the measuring tape snugly against you and parallel to the ground. Take a few deep breaths to let the tape rest on its most comfortable position (but not too loose!). If it falls on the half-inch, just round up. That's your bust size!

Step 3: Determine Your Cup Size

Determining cup size is where things can get tricky because cup sizes can vary depending on the maker. The most common way to calculate your cup size is by subtracting your band size from your bust size and using the difference to find your cup size according to a bra size chart.

Bra Size Chart

It's not uncommon to have different sized bras from one brand to another. That discrepancy happens because different bra sizes often have similar measurements with slight variations in cup and band sizes.

So, let's get down to the nitty-gritty of your bra size. Start with your current bra size and use the chart below to help refine your bra size estimation and fit.

Do You Have the Right Bra Size?

The only way to tell whether the bra size given to you by a bra size calculator and chart is right is to put it to the test. Try on bras in your size from different brands and see whether you get the same comfort and support from each one.

What the right fit feels like:

  • The straps stay put on your shoulders and don't dig in.
  • The band sits snugly against your back on any hook, ideally the loosest one. There should only be enough room to slide one finger underneath the band.
  • The cups properly cover your breasts with no overflow or gaps.
  • The underwire sits comfortably under your breasts.

You can also look at it the other way and determine whether you have the wrong bra size based on the tell-tale signs of a bad bra fit: cup gaps, straps and bands that are either too loose or tight, band riding up, etc.

What the wrong fit feels like:

  • The straps dig into your shoulders leaving painful marks, or slide off, especially if they're adjusted to the tightest fit.
  • The band feels too tight or loose, especially if it squeezes or rides up on the loosest hook or slides around on the tightest hook.
  • Your breasts overflow out of the cups or the cups have gaps.
  • The underwire sits on top of your breasts (not only uncomfortable, but defeats the whole purpose of an underwire!).

Either way, it won't take you long to know whether you've got the right or wrong bra size. Good bras are comfortable and supportive. Sure, there are plenty of good bras out there, but on top of comfort and support, the best bras are also available in a wide range of sizes, styles, and designed for versatility – which can be hard to come by if you don't know where to look.