What Is the Smallest Bra Size?

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Women come in all shapes and fit into bras that have a wide range of sizes. Every woman is unique in her own way and has individual needs from a well-fitting bra. In this article, I talk about small bust sizes, what is the smallest bra size, and the perfect lingerie for this size.

What Is the Smallest Bra Size?

The smallest bra size available is 28AAA. That means the band size is around 28 inches, perfect for ultra-slim ladies. And when I say “AAA,” we’re talking about a cup size where the breasts extend less than an inch from the rib cage.

Graphic image of a woman wearing a pink top that explains that the smallest cup size is 28AAA

Is A Cup the Smallest Bra Cup Size?

No, an A cup is the smallest family of cup sizes, but it isn’t the smallest bra size. AAA is the smallest size, followed by AA, followed by the A cup size.

Don’t worry, its totally normal to be confused, as sizing works the opposite when you get to larger cup sizes (example: DD cup is bigger than a D cup).

Here is a breakdown, small to large:

Bra SizeOverall Size
AAVery Small

What is the Smallest Cup Size?

AAA is the smallest cup size, but it isn’t really that simple. Cup size is only one half of the equation, with the band size being the other component.

So, as an example, a 28AAA is the smallest cup size. But a 32AAA is not technically the same cup size – it is a bit larger because the band size is larger.

What is the Average Bra Size?

The average bra size in the United State is 34DD, while the average bra size in the United Kingdom is 36DD.

Surprised? Yeah, me too. I personally don’t feel like I know a ton of women in those sizes. But, using that as a data point can be deceiving.

There are a couple factors at play here. For starters, most women are wearing the wrong bra size, so make sure to accurately calculate your size – you might be surprised!

Next, keep in mind that styles and brands are always evolving… and thus so is sizing.

A woman wearing a pink lace bralette and black shorts seated near a window

Other Small Bra Sizes Defined

When it comes to determining the smallest bra size, there are two factors to consider:

  • Cup Size: The AAA cup is the smallest, followed by the AA cup, and then the A cup. This can be confusing, because it works the other way when you get to D cups (DD is bigger than D).
  • Band Size: 28 is the smallest band size, with 30 being a bit larger, and 32 being even larger and more common.

Other small bust sizes include:

  • 28A bra cup: Reserved for a very petite lady with small breasts.
  • 30A bra cup: A slightly larger torso with the same breast size as 28A, this size is a little more common.

As evident from the measurements, breasts that fit into any of these bra sizes will be small.

While you may feel that you do not need a bra, the truth is that even a petite bust can benefit from a quality bra. It can provide support, create some curves, and give you a cleavage.

A dark blue racerback sports bra and leggings are worn by a woman seated on a brown couch

Features of a Bra for Smaller Breasts

When buying a new bra, you have to ensure that it is the correct size. Contrary to popular belief, even a small bust needs supportive, fitted bras as the breast tissues are prone to sagging regardless of size. Moreover, the following bra features can be helpful for small breasts:

  • Padded cups: Depending on your preference, you can choose whether you want light or thick padding. Ideally, a small bust benefits from light padding for a natural look.
  • Underwire: Underwire can lift the breast tissues and bring their weight closer to the center, giving them a desirable rounder shape.
  • Spaced-out cups: Small breasts are often set wider apart, so it makes sense to look for bras with spaced-out cups. Usually, a one-inch gap between the cups is perfect for tiny boobs.
  • Half cups: While coverage is important, it is not a priority for smaller boobs. Hence, look for the best demi cup bras or push up balconette bras that can provide you with a perkier shape that looks fuller on the top.

Comparing Small Bra Sizes

Bra Size Bust Size Band Size Weight Best Bra Style
28AAA 28 inches28 inchesLess than a poundBralette, adhesive, bandeau
28A 28-29 inches24-26 inchesLess than a poundPush-up, strapless, balconette
30A 30-31 inches26-28 inchesAround 1 poundPadded, wired, demi

Best Bras for Smaller Bust Size

Wearing the correct bra makes all the difference in the world, regardless of your bust size. Moreover, with the lingerie industry becoming more inclusive, it has become easier to find the perfect bra that targets your individual needs. Below, I have outlined the must-have bras for smaller breasts.

Padded Bras

Bra cups are primarily responsible for providing coverage to prevent your nipples from peeking through the attire. Everything from the cups’ shape, dimensions, and spacing matters when choosing a bra. For smaller busts, the most important factor is the padding in the cups.

A padded bra for small breasts has a thin foam between the fabrics of each cup, which can alter your silhouette and enhance your bust line. It can help make your boobs look fuller and firmer. Therefore, if you feel conscious about your breast size, you can check out the range of bras that come with different padding.


A bralette is designed to provide comfort along with support. It lacks the structure of a proper bra, yet retains enough features to make it a viable option for a small bust. It has soft and simple cups, a prominent band, and thin straps. It looks more like a crop top than a bra.

A white bandeau lace bralette and denim shorts are worn by a woman

Push Up Bras

The next on the list is the classic push-up bra. This bra also has padded cups. However, the padding is situated towards the bottom of the cups at an angle that lifts the breast tissues. When the boobs are pushed upwards and inwards, you get a hint of cleavage.

Most of the best push-up bras for A cups come with an underwire that stabilizes the bust and adds to the lifting effect. They also have half- or demi-cups that work splendidly under low necklines. Therefore, if your dress or top calls for a striking cleavage, go for a comfortable, perfectly sized push bra.

Related Questions

Which Bra Size Is Smaller, A or AA?

The size AA is smaller than size A. A cup size denotes a one-inch difference between the bust and band sizes. Contrarily, size D is smaller than size DD, which can cause some confusion when people compare sizes A and AA.

What Is a Normal Breast Size?

There’s no exact normal breast size because every size is normal. However, the average breast size among women around the world falls under A and B cups.

How Will I Know if I have a Small Bra Size?

You will know you have a small bra size if your band and bust measurements fall under A to B sizes. However, a person can have a broad band size yet a small cup size.

Bra Size Measurement & Cup Size | A, B, C, D, DD Bra Sizes AND Extra Large Breasts


The smallest bra size is the combination of the smallest band size, 28, and the smallest cup size, AAA. This size is most common in teenagers or girls with developing bodies. However, I would like to conclude by saying that small or big, women with all kinds of breast sizes are unique and beautiful.


Allena is the Founder and Editor of The Better Fit, a platform dedicated to empowering women with practical advice on bras and fitness, inspired by her own revelation of the widespread issue of incorrect bra sizing. Her expertise and tips have been recognized by major publications such as Cosmopolitan, Better Homes & Gardens, Insider, and NBC, making her a trusted voice in women's wellness and lifestyle.