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

Discreet packaging · Shipped Securely

Pay later with Shop Pay, Sezzle & Afterpay

38K Bras

(9 products)

How a 38K should fit

A 38K 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 40JJ

A 38K means a 38-inch band with a K cup — roughly a 15-inch difference between your underbust and your bust measurement. Cup letters are not consistent between markets: UK-sized brands like Panache run a different ladder to US labels, so your 38K may sit a letter along depending on who made it.

How a 38K should fit

A 38K 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 if 38K isn't right

Band digs in — 40JJ gives the same cup volume with more room
Cup gapes at the top — try 38JJ

Best 38K styles

Look for side support panels, which push tissue forward and stop it migrating under the arm — the single most useful feature at 38K. 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.