Size 40JJ Bikinis
Also labeled US 40N and EU 90N
A size 40JJ bikini is the absolute pinnacle of what we carry in a 40 band — a size that almost no retail swimwear brand acknowledges exists. A larger band paired with a JJ cup requires engineering that solves genuinely complex problems around volume, weight, and support. At this size, your size 40JJ bikini isn't just clothing; it's essential infrastructure that has to perform flawlessly. We've curated this collection for 40JJ customers who understand that fit at this level is completely non-negotiable. Every style here has been selected because it delivers the specialized support and genuine engineering that only makes sense at a 40JJ.
What to Look For in Size 40JJ Bikinis
When shopping for a size 40JJ bikini, every structural detail becomes critical. Look for cups with substantial internal architecture — multiple seams creating structural zones, internal boning, or molded sections that maintain shape under real volume. Your band needs to be constructed from firm, recovery fabric that doesn't stretch out; thin fabric will fail within a season. Underwire (when present) should be fully encased and support the entire base of your cup — partial encasement won't hold at a 40JJ. Straps should be wide, reinforced, and positioned well back on the shoulder where they can actually bear load. Avoid anything with decorative details that compromise structural integrity. At a size 40JJ bikini, every element is functional, not aesthetic.
Cup-Sized Bikinis, Curated by Fit Experts
At The Bra Diva, we carry bikinis the same way we carry bras — by actual bra size, not just by small, medium, or large. Every style in this collection is selected for its construction quality, true-to-size fit, and ability to hold up in and out of the water. Our team has been fitting customers since 1987 at our Cherry Hill, NJ boutique, and we bring that same expertise to every size we carry online.
Shopping for more styles in size 40JJ? Browse our Size 40JJ Swimwear collection, or shop Size 40JJ Bras for everyday lingerie in your size.
Not sure if 40JJ is your correct size? Use our bikini size chart →