How to Use a Bra Size Chart to Find Your Perfect Fit

Find Your Perfect Bra Fit

Finding your bra size can feel like navigating a windy maze, but with the right tools, it's simpler than you think. A well-designed bra size chart is critical to unlocking a world where comfort meets impeccable fit. Let's break down how to use a bra size chart to secure your dream fit effortlessly and with your preferences carefully considered.

Before we strap in, clarifying some basics is essential. Every great fit starts with accurate measurements. A bra measurement chart can help you transform your numbers into the perfect size. Here’s how to get started.

How to measure your band size:

What you wear matters! Start with a non-padded or lightly padded bra, or go full birthday suit if you’re alone. We find that the best fit is when you don’t add a lot of extra bulk or compression to your measurements.
Measure Your Underbust: Wrap a measuring tape snug, but not tight, around your ribcage, right under your bust. Ensure the tape is straight and level around your body. This measurement, in inches, is your band size. If you get an odd number, round up to the following even number for the best fit.

Note: this is a departure from ‘old school’ bra fitting methods. In the past, and with other brands, you might find instructions to add 4 to 5 inches to your measurement to get your band size. This method is outdated because we make bras out of stretchy materials nowadays, but that wasn’t the case when this method first appeared. Don’t worry about adding anything unless you’re on an odd number OR if you can’t stand a snug, supportive band.

Band Size Variation for Comfort: Take a deep inhale before you measure to expand your ribcage to the largest it might be, and you’ll get a more comfy-fitting band size.

How to measure your cup size:

Measure Your Full Bust: Now, measure around the fullest part of your bust, keeping the tape level but not too tight. This measurement gives you your bust size, which is crucial for determining your cup.
Determine Your Cup Size: Take your full bust measurement and subtract your underbust measurement. This equation tells you the cup size. Each inch of difference represents one full cup size. For example, a 1" difference = A cup, a 2" difference = B cup, and a 3" difference = C cup, etc. A bra chart is convenient here because the cup sizes shift after D and go to DD (US) or E (UK), depending on the brand's reference.

At iteration, we use alpha-sized bras with a fuller bust option, as our garments are very fit-flexible. To find your size in our bras, you'll need to take both measurements you've found, consult the size chart, and see where your two measurements intersect.

Align Your Measurements with a Bra Size Chart

With your band and bust measurements, you’re ready to consult a bra size chart. A bra size chart helps you translate those numbers into specific sizes based on the brands’ fit methods.

With iteration bras, we size differently since the fit is a bit more flexible. To find your correct size, we recommend following our size chart below. The best way to ensure a great fit is to take your measurements before ordering. Our bodies fluctuate and change over time, so a recent measurement is much better to compare vs. one from the distant past.

Before we jump right into the size chart, we want to mention that at iteration, we offer two options to ensure you find the perfect fit: Standard and Fuller Cup. Here's a chart to outline the differences to the way they fit.

Standard vs Fuller Cup	Standard Sizes	Fuller Bust Sizes
Size Range	XS through 3X	XS+ through 3X+
Suitable For	Best for cup sizes A through D	Best for cup sizes DD through G
Band Sizing	Fits band sizes 28" to 50"; band length adjusts 2" for each size up or down.	Fits band sizes 28" to 50"; Fuller Cup bands are 1" smaller than their Standard sisters for added support; band length adjusts 2" for each size up or down.
Details	Designed to provide a comfortable and supportive fit for various body types; best suited for smaller to mid-size busts.	Slightly taller side seams, center fronts, and deeper cup molding offer additional support and coverage.

Reminder: Don’t go ONLY by the charts; your preferences matter, too, so be sure to follow along and determine where you prefer support vs. comfort in the mix.

iteration bra size chart

Before you pick your size, decide your comfort + support preference.

Knowing your size is just the beginning. A big part of bra fit is how you want to feel in your bra. Some women with larger busts want a very firm, snug, and supportive bra because that helps them feel their best. Others might feel better with a looser, more comfy fit that doesn’t grip the body so tightly.

You might be unsure which size to pick if you’re between a D + DD cup. Consider how you prioritize comfort and support:

You Prioritize More Support // Choose the Fuller Cup (+) size for a snugger fit, extra lift, and cup room. If you are full on top, you may prefer this option to avoid a digging neckline.
You Prioritize More Comfort // Choose the Standard size for a more relaxed band fit.
You Prioritize Maximum Comfort // If you prefer even more comfort and similar cup coverage to the Fuller Cup, consider sizing up to the next size up in the standard range.

For example, if your underbust measures 32" and your fullest bust is 37", we would typically recommend a size S+. However, if you prefer a slightly more relaxed fit, a Standard Small might be the better choice, offering an extra inch in circumference for added comfort. You might consider a size Medium if you like a very comfortable fit around the band and additional cup coverage.

Using a bra size chart isn't just about numbers and measurements; it's about empowering yourself with the knowledge to choose bras that uplift, support, and celebrate your body. If you’re still unsure what size is right for you, please email us at team@iterationera.com, and we’ll help you get the right size from the start.