Comparing Cup Sizes: A vs. B vs. C vs. D Cup Size

There are a few specific categories I like to consider when choosing a bra. Whether it's for a Leonisa shopper or myself, my focus is always on the quality elements that make up a great bra and allow it to perform and fit well. I look at things like cup and band material, straps (if there are any), overall bra style, level of padding, support and cup size. When helping another woman find her best bra, I shop within her style criteria and list of desired results using these categories with special focus on the cup size.

I get questions about cup size all the time, with inquiry subjects ranging from specific bra styles and different types of bra cups to determining a general cup size that is reliable regardless of bra style, material or band width. My answer to all of these questions looks something like the following: Your unique cup size is subject to change alongside different bra factors and has to do primarily with measurements! If you have similar questions, know that you're not alone. I'm here to help you find the cup size and associated band size that works best for you. To help explain this in detail, I have created a comparison guide for cup sizes A-DD that also includes helpful tips for finding your overall best bra size or sizes. Let's get started, shall we?

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Finding the Right Cup Size

When it comes to finding a bra, cup size is not something you should take as a general suggestion. Your cup size is something worth determining in specificity because an accurate cup size match helps your bras fit better. During your time as a bra wearer, it's probable that you've experienced a few annoying effects of wearing certain traditional bras. These common bra issues might include red marks on your skin, spillage, skin bulges and more. More often than not, these issues can be solved by a change in cup size! By making a cup size change, you will create a better fit around your breast and prevent further issues.

Your cup size refers only to the size of the cup itself and not the entire bra or any other part of it. As cup size gets bigger and moves in alphabetical order from the letter A onward, the bra cups become deeper and wider. Cup size is measured by the bust measurement (including the breasts) minus the rib cage measurement taken just underneath the breasts. For example, a woman with smaller breasts might fit best in an A or B cup size while those with larger breasts might fill out a C or D cup.

Cup Size Comparison Guide

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Now that you're familiar with the specifics of cup sizing, it's time to have a little side-by-side comparison between different cup sizes. This is helpful if you already know your cup size or if you are still in the process of determining yours. Each section features an in depth description of the cup size and how it relates to overall bra size. I've also included a few notes on each cup size including shopping tips, material suggestions and the best bra styles for each cup size.


Comparing Cup Sizes: A vs. B Cup

Both A and B cup sizes make up the smaller end of the cup size spectrum. However, just because these cup sizes are smaller does not mean that they don't require a supportive bra. It's important to wear a bra even if you have an A or B cup because it gives you the support you need and the smoothing power you desire underneath your clothing. If your breasts fall into one of these cup size categories, it's also important for you to wear a sports bra when working out or engaging in high-impact activity. This will keep you comfortable and help prevent any muscle tearing in the chest area.

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Do you think your cup size is an A or B? Grab your measuring tape and find out! If your bust measurement, which measures all the way around your rib cage including your breasts, minus your band measurement, which measures all the way around your rib cage just under your breasts, equals exactly or close to one inch, then your regular cup size is in the A category. If that measurement - we'll call it the cup size measurement - is closer to two inches, then you're in the B cup category. Both of these cups work well with just about any bra styles, but I do have a few notes on each to help with shopping and styling.

Best Bra for A Cups: If your boobs are on the smaller side and A cups fit you best, then you can rock just about any style of bra! There are even special petite bras available for those of you with a small overall frame.

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Best Bra for B Cups: If an A cup size isn't quite enough and you're beginning to see spillage, bulging or both, give yourself a little more room in the cups and try out a B cup. The difference between one cup size to the next is the same, but sometimes switching from A cups to B cups makes an entire world of difference. B cups can be enhanced easily, but they also look great without much enhancement at all. Take advantage of this size if you have it and rock a cute and flirty bralette! This stylish yet comfy bra style is made to be shown off and gives just the right amount of support for B cups.

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Comparing Cup Sizes: B vs. C Cup

As my list of cup size comparisons begins to grow from A to B cups and beyond, consider the C cup to be a midway point of sorts. If your breasts have their best fit inside a bra with C cups, you have so many great options when it comes to bras and what they can do for you. Of course, this is not to say that the little sister B cup doesn't have anything to offer. Let's compare.

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A pair of B cups presents enough to show off and enhance, but they're also easily secured for running and other high impact workouts. If you're looking to take your B cups to the next level, look no further than a high push up bra, which will take you from B to C - and maybe a little further - in no time. For those of you who comfortably fill C cups without push up power or other bra enhancements, know that there is no shortage of ways for you to wear a bra, either. Your size C cups might look best in a soft bra made of t-shirt fabric or a wireless bra, though a traditional underwire bra is a solid option for optimum support and shaping power.

Best Bra for C Cups: I think C cups are a lot like blondes in that they get to have all the fun. In addition to a great everyday bra with ample support, your C cups deserve to be shown off in different styles of sexy bras! Fun, sexy bra styles can vary in cup shape and other elements, but your mid size C cups will fill out any style beautifully. Go for sexy bra styles with mesh cutouts, sleek fabrics, sultry color combinations and more.


Comparing Cup Sizes: C vs. D and DD Cups

The graduation from C to D cups can be surprising at times. I've found there is a bit of gray area between C cups and D cups, and that's mostly because the two cup sizes generally include those with similar band sizes. The distinction between D and DD cups can get even foggier. If you remember, we talked about band size earlier and how it customizes the fit and support level of your bra in addition to the cup size. The band size can also give you a bit of wiggle room in terms of cup size, and I see most of that happening between C, D and DD cups. This is also known as your bra sister size and often comes in handy if your regular bra size isn't in stock or you want to try different cup and band size combinations for a more customized fit.

If C cups are the midpoint or medium breast size indicator on the cup size scale, then D cups mark the transition towards larger breasts and DD cups are the exact opposite of A cups. You see, C cups are quite versatile and, like B cups, tend to fit nicely into a diverse selection of bra styles while still looking natural in shape and proportional to the body. On the other hand, to my ladies with lovely, large D cups or DD cups, you're blessed with the size push-up bras were designed to emulate. Take care of them, support them and, most importantly, flaunt them!

Best Bra for D Cups: My rule is that larger cup sizes should be met with more support. For D cups, I recommend a supportive underwire bra to keep those D cups lightly lifted and securely in place all day long. Thankfully, Leonisa has the most comfortable underwire bras on the planet in an impressive range of styles.

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Best Bras for DD Cups: Underwire bras are a great everyday option for DD cups, too! In addition to having a few underwire styles in your bra rotation, I like to recommend a minimizer bra for those times when you need a little extra support. These bras offer a smoothing effect around the cups, under the arms and in the back area for a seamless and sleek look underneath your clothing.

Cup Size vs. Band Size

Aside from your cup size, your overall bra size also includes your band size. The band is the portion of the bra under the cups and straps that wraps around your chest and back. Depending on the style of bra you prefer, your band might clasp in the back via two or three hooks, clip together in the front between the cups or feature a clasp-less design that is meant to be pulled over your head. Regardless of band type, your specific band size is the same as the number of inches in your chest measurement as measured just under your breasts in the rib cage area.

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An accurate band size is important because the band is responsible for overall bra support. The band should fit securely, feeling snug but not too tight, in order to create a good bra foundation and shape when combined with the cups and straps. If you've ever felt generally unsupported by your bra or felt like your breasts were moving around too much during wear, you might have been wearing a band size that was too large. On the other hand, bands that are too small present their fair share of problems as well. If you notice rib cage pain, difficulty breathing or that your straps fall down a lot, consider reevaluating your band size in order to eliminate these problems and get a better fit.

Finding Your Perfect Bra Size

I prefer to buy all my bras online and try them on in my own home, which is why I know it's important to be informed about the difference in cup sizes. If you're still unsure of your real bra size, don't worry. Take the Leonisa bra size quiz, a step-by-step bra size finder, and you'll know which size or sizes to order so you can spend less time making returns and more time enjoying your perfect bra.


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