Understanding the 40A Bra Size: Fit and Confidence

May 28, 2025

Written by Carmen Rodriguez

Understanding the 40A Bra Size: Fit and Confidence. In the world of bras, no size is more or less important than another, it’s all about finding what fits your body comfortably and accurately. For women who wear a 40A bra size, navigating the lingerie aisle can be especially frustrating. This size combines a larger band with a shallow cup, which means that the 40A bra is designed for those whose chest measurement is broader, but whose bust projection is more modest, resulting in a unique fit that relates closely to overall chest and body shape. Finding the right support and style can enhance both comfort and appearance, often requiring expert guidance. The 40A bra size is often chosen by women with a full figure, particularly those with broader frames or fuller ribcages who need a larger band but a smaller cup.

At Olivia Paisley Intimates, we believe that every body deserves comfort and beauty, regardless of size or shape. This blog dives into the details of the 40A bra, what it means, and also notes that cup sizes can go as small as AAA, which is often marketed for flat-chested individuals, to provide context for the A cup, what to look for, and how to shop with confidence.

Introduction to Bra Sizes

Bra sizes can seem complicated at first, but understanding the basics is the key to unlocking your perfect fit and feeling truly comfortable in your own skin. Every bra size is made up of two parts: the band size and the cup size. The band size, or bra band, is the number that measures the circumference of your torso just under your bust, while the cup size is the letter that represents the volume of your breasts. Together, the band and cup size work to provide the right support and shape for women of all body types.

For example, a 40A bra size combines a larger band with a smaller cup, making it a great choice for women with a broader torso and a smaller bust. Petite women, on the other hand, might find that a 34A or 32A fits their smaller frame and proportions better. No matter your size, the goal is always to find a bra that feels comfortable, offers the right support, and enhances your natural shape.

When shopping for bras, it’s helpful to use a size chart to compare measurements and find your ideal fit. Many brands and websites offer filters by size, color, and style, making it easier to shop for exactly what you need. There are so many styles to explore, strapless bras for special occasions, sports bras for active days, wireless bras for all-day comfort, underwire bras for extra lift, and bralettes for a relaxed, smoothing feel. Lace bras add a touch of beauty, while smoothing bras help create a seamless look under clothes.

The right bra can make a world of difference in how you look and feel. Whether you have a smaller bust or need a larger band, there’s a perfect fit out there for every woman. Don’t be afraid to try different styles, features, and brands until you find the one that makes you feel happy, confident, and supported. Remember, a comfortable bra is more than just an undergarment, it’s a key part of your wardrobe that helps you love the way you look and feel every day.

What Does a 40A Bra Size Mean?

Bra sizes are a combination of band size (the number) and cup size (the letter). When shopping for bras in the lingerie aisle, a 40A means:

Band Size (40): This refers to the measurement around your torso just under your bust. A 40 band size is generally considered a plus size or full band size.
Cup Size (A): The A cup represents a modest bust volume, meaning the difference between the bust and band measurement is about 1 inch.

This size is common among women with broader frames or fuller ribcages but smaller breasts. It’s important to note that a 40A is not the same as a 38B or 42AA, even though the cup may appear similar in volume, the band fit will be different. If the band is too tight, it can cause discomfort and negatively affect the overall fit.

A 38B has the same cup volume as a 40A but the band is narrower (38) and the cup is deeper.Pepper specializes in bras specifically for small cup sizes (AA, A, B) with diverse band ranges.Soft molded cups or light padding provide gentle shaping without creating bulk for 40A wearers.Adjustable and wide straps help distribute weight and avoid shoulder digging for 40A bras.T-shirt bras are seamless and smoothing under clothing, making them a good choice for 40A wearers.Front-closure bras are easier to put on and take off, especially with a wider band for 40A wearers.Bralettes designed for full bands support a 40 band without oversized cups, suitable for 40A wearers.Caring for 40A bras involves washing in cold water and air drying to maintain their shape and longevity.

Common Fit Challenges for 40A Wearers

Cup Gaping:Since A cups are shallow, some styles may gape or wrinkle if not designed for smaller busts or for petite women with petite frames.
Band Rolling or Riding Up:A poorly fitted band can ride up the back, causing discomfort and lack of support.
Limited Availability:Many mainstream brands don't carry extended band sizes with smaller cups, which can make shopping frustrating.

What to Look For in a 40A Bra

✅ Soft Molded Cups or Light Padding

These can provide gentle shaping without creating bulk. Look for bras that contour the body for a smooth silhouette. Minimizer bras can also be a good option for those seeking a smoother look or less projection.

✅ Adjustable and Wide Straps

To better distribute weight and avoid shoulder digging, especially important with wider bands, look for bras that feature adjustable, wide, and comfort straps.

✅ Full Coverage or Demi Styles

Full coverage offers modesty, while demi cup bras offer lift without overwhelming a smaller bust. Side support panels can also help provide a better fit and shape for 40A wearers by supporting and shaping the sides of the bust.

✅ Wire Free Support Options

For everyday comfort, many 40A wearers prefer wireless bras that still offer structure through smart seaming and design. Seamless wireless bras are also a popular option, providing a smooth look under clothing.

Best Sports Bras and Styles for 40A

T-shirt Bras: Seamless and smoothing under clothing.
Wireless Bras: Great for casual wear and comfort first days.
Front-Closure Bras: Easier to put on and take off, especially with a wider band.
Bralettes Designed for Full Bands: Look for size inclusive bralette lines that support a 40 band without oversized cups.
Strapless Bras: Ideal for special occasions or outfits that require bare shoulders.

Caring for Your 40A Bra

Taking good care of your 40A bra is key to enjoying lasting comfort, support, and a perfect fit every day. Whether you prefer sports bras for active days or classic shirt bras for everyday wear, following a few simple care steps can help your favorite styles look and feel their best.

Start by washing your bras in cold water with a gentle detergent to protect the fabric and underwire. For delicate styles, like lace or sports bras, hand washing is ideal to prevent stretching or shrinking. After washing, gently reshape the cup and lay your bra flat to air dry, avoiding direct sunlight and heat, which can damage both the band and the cup.

Regular cleaning is especially important for women with sensitive skin or those who wear their bras during workouts. Washing after each wear helps keep your bras fresh and prevents the buildup of bacteria. When it comes to storage, avoid folding or creasing your bras, as this can distort the cup and underwire. Instead, store your bras flat in a cool, dry place, keeping your white and black bras looking crisp and new.

Shopping for new size bras? Explore different brands and styles to find your perfect fit. Many brands now offer a wide range of sizes, including 40A, so you can find results that match your needs, whether you’re searching for a supportive underwire bra, a comfortable wireless option, or a versatile shirt bra. Use filters by size, color, and style to quickly find what you’re looking for, and don’t forget to check the size chart and read reviews before adding your favorites to the cart. Checking a reputable website can also provide images and detailed explanations about bra sizing and care. You can follow a link to additional resources or guides for more support.

By caring for your bras and choosing the right styles and brands, you’ll ensure that every 40A bra in your collection remains a reliable, comfortable, and confidence boosting part of your wardrobe.

Olivia Paisley Intimates: Where Comfort Meets Confidence

At Olivia Paisley Intimates, we are committed to designing and curating bras that cater to every size, not just the most common ones. As an inclusive brand, we offer an extensive size range to ensure everyone finds their perfect fit. Our selection of 40A bras blends beautiful fabrics, supportive construction, and everyday wearability.

We recommend looking into our soft lace contour bras, wire-free t-shirt bras, and convertible plunge styles, all available in extended band sizes, including 40A. Because everyone deserves to feel supported, seen, and celebrated.

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Final Thoughts

Finding the perfect 40A bra is about more than just numbers, it's about comfort, shape, and style that reflects you. With the right fit, women with this size can enjoy bras that lift, support, and flatter their bodies without compromise.

If you're unsure of your size, consider a professional bra fitting or reach out to our expert team at Olivia Paisley Intimates for personalized recommendations.

Need help finding your perfect fit?
Visit our Fit Guide or schedule a virtual fitting with one of our certified lingerie specialists. Because the right bra can change how you feel in your clothes and in your skin.