Ships in 24–72 hrs · Free U.S. shipping $50+

Discreet packaging · Shipped Securely

Pay later with Shop Pay, Sezzle & Afterpay

34K Bras

(10 products)

How a 34K should fit

A 34K is a full-bust size, and the engineering matters more than the label. Wide side wings, a firm band with four hooks and seamed cups will outperform a prettier bra with thin straps every time.

Sister sizes to try

Band digs in — try 36JJ

34K pairs a 34-inch band with a K cup, which works out at about a 15-inch gap between underbust and bust. Sizing varies more between brands than most people expect, which is why two bras both marked 34K can fit quite differently.

How a 34K should fit

At K cup, weight distribution is the whole problem. A 34K needs a taut band, a centre gore that sits flush against the sternum, and cups built in three or four panels — a single moulded cup simply cannot hold this volume in shape.

Sister sizes to try if 34K isn't right

Band digs in — 36JJ gives the same cup volume with more room
Cup gapes at the top — try 34JJ

Best 34K styles

Look for side support panels, which push tissue forward and stop it migrating under the arm — the single most useful feature at 34K. Full cup and balconette shapes both work; strapless is harder at this size and worth trying with a longline style, which spreads the weight across a wider band.