Size 30C Bikinis
At 30C, you're wearing a small band with a moderate cup — a size that sits in that sweet spot between delicate and balanced. If you've ever grabbed a medium bikini top and found it either gaping or crushing your band, you know the frustration. A true 30C bikini top solves that problem by matching your actual measurements, giving you the support you need without the excess fabric that comes with standard sizing.
What to Look For in a 30C Bikini Top
When you're shopping a 30C, construction matters more than size alone. Look for bikini tops with structured cups — not flimsy panels that rely entirely on the band for support. A good underwire or molded cup at 30C will have enough coverage to hold up through swimming and movement without gaping. Pay attention to the band itself: at a small band size, you want straps that won't slip inward on your shoulders, so check that the strap placement sits on the outer edge of your shoulder, not creeping toward your neck. Finally, verify the size before purchasing — brands vary, and some use "small" or "XS" instead of actual bra sizing. We list every bikini by its true cup size, so you know what you're getting.
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 30C? Browse our Size 30C Swimwear collection, or shop Size 30C Bras for everyday lingerie in your size.
Not sure if 30C is your correct size? Use our bikini size chart →