A well-fitting bikini top transforms your beach experience. The wrong size means constant adjusting, poor support and discomfort. This guide walks you through everything you need to know to find the perfect bikini top.
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How Bikini Top Sizing Works
Bikini tops typically come in two sizing systems: standard sizing (XS–XL) and cup sizing (8A–16DD+). Standard sizing works well for A–C cups where volume and band don't need to be separated. For D cups and above, always look for cup-sized tops — the difference in support and fit is significant.
Measuring for a Bikini Top
- Measure your underbust (band size) and fullest point (overbust)
- The difference determines your cup size: 0cm = A, 2cm = B, 4cm = C, 6cm = D, 8cm = DD
- For swimwear, size up from your bra cup size — swimwear fabric stretches more than bra fabric
Bikini Top Styles
Triangle Tops
The classic style. Ties at the back and neck, fully adjustable. Best for A–C cups. Minimal coverage and minimal support, but iconic beach look.
Underwire Tops
Structured support for D+ cups. Looks like a bra, performs like one. Essential for larger busts who want to actually swim rather than just pose. Brands like Sea Level, Sunseeker and Baku excel here.
Bandeau Tops
Strapless style, best for A–B cups. Great for avoiding tan lines. Many styles include removable halter strap for extra security during activity.
Longline / Crop Top
Covers the midriff, on-trend, suits all cup sizes. Great for Darwin's reef and active water activities where coverage matters.
Halter Tops
Neck tie provides excellent support for B–D cups. Keeps everything in place during water sports and swimming.
Best Bikini Top Brands for Cup Sizes
- A–C cups: Seafolly, Tigerlily, Bonds Swim, Rip Curl
- C–DD cups: Baku, Sea Level, Sunseeker, Jantzen
- DD+ cups: Sea Level (specialist in full-bust swimwear), Sunseeker
Mix and Match Tip
Buying tops and bottoms separately means you can match different sizes on top and bottom — perfect if you're a different size up top versus the hip. Read our full Mix and Match Bikini Guide for inspiration and tips.
Shop Bikini Tops at Splash Swimwear
Browse our full range of bikini tops including cup-sized and standard-sized options. We stock separates from all major Australian brands so you can find your perfect fit.