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Check the band before anything else
Small-busted people are very often sold a band that is too big, because the cup letter that goes with their true band sounds wrong. A 30-inch ribcage with a small bust is a 30B or 30C, and is commonly sold a 34A. A loose band lets the cups hang away from the body, which looks exactly like a cup that is too big.
Measure your underbust and use the calculator. A smaller band with a higher letter frequently ends the gaping without any change of style.
Cup shapes that lie flat
- Soft, unlined cups. Fabric follows your shape. There is nothing to stand away.
- Triangle bras and bralettes. A triangle suits a shallow or conical small bust naturally.
- Demi and half-cup shapes. Less upper cup means less to gape.
- Plunge cuts in moulded bras. Lower at the top and centre than full coverage.
- Thin, flexible foam or spacer fabric, where you want a smooth finish.
- Graduated padding, if you want added shape. A pad that is thicker at the bottom fills the cup from below.
What to be wary of
- Deep, rigid, full-coverage moulded cups. The usual cause of a gap at the top.
- Uniformly thick padding, which holds its own shape whatever is inside.
- Wires that are too wide. In small cups on larger bands, wires often extend past the breast. Plunges tend to have narrower ones.
- Sizing down to stop gaping. The wire becomes too narrow and digs in.
By what you want from the bra
| You want | Try |
|---|---|
| Comfort and a natural shape | Unlined triangle bra or bralette |
| Smooth under T-shirts | Thin-foam plunge or non-wired moulded bra |
| More shape or cleavage | Push-up with graduated padding |
| Coverage only | Soft crop top or lined bralette |
| Sport | A compression sports bra in the right band size |
Where to buy
- High-street chains stock A and B cups from 32 bands upward everywhere, with AA in some ranges.
- Ranges that begin at 28A or 30A. Boux Avenue's sizing starts at a 28 band with an A cup, and Primark has extended popular ranges down to 28AA.
- Specialist small-bust brands, mostly online, design cups for AAA to B that are shallower than mainstream ones.
- Teen and first-bra ranges for small cups on small bands, in plain styles.
Small cups on bands of 38 and above are harder to find. See where to buy bras in unusual sizes.
Related guides
Size detail is in the AA cup guide and A, B and C cups explained. If gaping persists, work through why your bra cups are gaping.
Frequently asked questions
What is the best bra style for a small bust?
Soft cups, triangle bras and bralettes fit most reliably because they follow your shape. For a smooth look, choose a thin, flexible moulded cup in a plunge or demi cut. Avoid deep, rigid, full-coverage foam cups.
Why do bras always gape on me?
Usually because the cup is deeper or taller than your breast, not because it is too big overall. A loose band also lets cups fall away from the chest. Check the band first, then change the cup shape.
Are padded bras the only option for small busts?
No. Many shops fill their small-cup ranges with heavy padding, but unlined and lightly lined bras exist in AA to B cups. They are often more comfortable and fit more closely.
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