The 30H Bra: Understanding the Fit, Support & Style You Deserve

Finding a bra that truly fits can be challenging—especially if you have a small band size and a full cup, like those who wear a 30H bra. Too often, women with this combination are misfitted into sister sizes that lack support or shape. The result? Poor posture, discomfort, and lingerie that doesn’t work as hard as it should.

The 30H bra is not just a size—it’s a carefully engineered solution for women with narrow ribcages and a large bust. In this expert guide, we’ll break down what this size means, how to find the right fit, and where to shop if you need high-quality support without compromising on style.

What Does a 30H Bra Really Mean?

A 30H bra consists of:

• A 30-inch band (measured around the ribcage, just under the bust)

• A cup volume that's 8 inches larger than the band (i.e., bust measurement around 38 inches)

Importantly, cup size is not static across band sizes. A 30H is equivalent in volume to a:

• 32GG

• 34G
  This is called “sister sizing,” but note that while the cup volume may be similar, the band fit is not. If you have a 30-inch underbust, a 34G will feel far too loose and provide inadequate support.

Who Is the 30H Bra Designed For?

You may be a 30H if:

• Your underbust measures around 28–30 inches

• Your full bust measures 38–39 inches

• You experience cup spillage or underwire digging, even in DDD or G cups

• You find most bands ride up your back, causing shoulder strain

Women with petite frames and fuller busts often fall into this category, and yet it’s one of the most underserved size groups in mainstream lingerie.

Why Proper Fit in a 30H Bra Matters

1. Support

A snug 30 band is essential to lift and anchor the bust. Without it, the weight shifts to your shoulders and causes strain.

2. Comfort

A bra that fits well won’t pinch, gape, or dig. With a proper 30H, the band sits flush and the cups contain the entire breast without overflow or wrinkling.

3. Posture and Health

Wearing a band that’s too loose or a cup that’s too small can lead to back pain, shoulder grooves, and poor posture over time. A well-fitted 30H offers structural support that promotes alignment and reduces fatigue.

Best Styles for 30H Bras

Not every bra style is built to handle the demands of a full bust on a petite frame. Look for these styles that support and flatter:

• Full-Cup Bras: Provide complete breast coverage and optimal support.

• Balconette Bras: Lift from the bottom and offer a rounded, uplifted shape.

• Side-Support Bras: Feature reinforced panels to bring breast tissue forward and create a flattering silhouette.

• Minimizers: Useful if you want to create a smoother look under button-up shirts.

• Underwired T-Shirt Bras: Offer seamless shaping and firm support under clothes.

Where to Buy 30H Bras

Top Brands That Cater to 30H Sizes:

• Panache – Known for structure and reliability

• Freya – Offers fashionable designs with extended sizing

• Elomi – Specializes in full-bust and plus-size fits

• Curvy Kate – Bold designs and inclusive cup sizes

• Bravissimo – Full-bust focused with a wide range of styles

• PrimaDonna – Luxury-level craftsmanship for H cups and beyond

Many online retailers such as Bare Necessities, HerRoom, and Figleaves also carry a wide selection of 30H bras.

Common Fit Mistakes in 30H Sizing

1. Wearing a larger band to “make room”: This sacrifices support and causes bras to shift or ride up.

2. Choosing stretchy bands: You need a firm, reinforced band that holds its shape over time.

3. Settling for shallow cups: Full-bust bras need cup depth and side support to contain and shape the breast properly.

Bra Fitting Tips for 30H Wearers

• Use a professional fitting guide or service (in-person or online) to confirm your size

• Always scoop and swoop—adjust breast tissue fully into the cups when trying on bras

• Try multiple styles—different cuts work better for different breast shapes (projected, full-on-top, wide-set, etc.)

• Don’t rely on U.S. sizing alone—UK brands often offer better extended sizing options and clearer cup increments

Final Thoughts

Wearing the right size bra is more than a number—it’s about support, self-respect, and understanding your body. The 30H bra is designed for women who need maximum lift in a minimal band, and the good news is, more brands are embracing this once-overlooked size.

If you’ve been living in uncomfortable bras, constantly adjusting straps, or settling for ill-fitting cups, it may be time to explore the fit freedom a 30H can provide. Support should never be a luxury—it should be your everyday standard.