How to Measure for a Bikini Top and Bottom
Two pieces, two decisions. Top: S/M/L for A–C cups, band-cup sizing for D+. Bottom: hip measurement to match the cut. Here's the guide.
Top: Two Sizing Systems
| System | Best for | Notes |
|---|---|---|
| S/M/L letter sizing | A through C cups | No structure, soft cups; minimal support |
| Band-cup sizing (32D, 34DD) | D+ cups required, A–C cups optional | Underwire, structured cups, real support |
| Combined (e.g., M/D) | Some brands | Letter for band, letter for cup |
D+ cups need structure
S/M/L Top Sizing
| Bust | Cup likely | Letter top |
|---|---|---|
| 31–33" | A | XS / S |
| 33–35" | A–B | S |
| 35–37" | B–C | S / M |
| 37–39" | C | M |
| 39–41" | C–D (need band-cup top) | M / L |
| 41–43" | D+ (band-cup mandatory) | L (only with structure) |
Bottom Sizing by Cut
| Hip measurement | Brief / Hipster | Cheeky | Brazilian |
|---|---|---|---|
| 33–35" | XS / S | XS | XS |
| 35–37" | S | S | S |
| 37–39" | M | M | M |
| 39–41" | M / L | M / L | M / L |
| 41–43" | L | L | L |
| 43–45" | XL | XL | XL |
Cheeky and Brazilian bottoms don't run smaller — same hip measurement maps to the same letter size. The smaller seat coverage is design choice, not undersizing.
Common Mistakes
Buying L bikini top for D+ cup
Soft-cup tops can't support D+ bust. Use band-cup sizing with structure.
Sizing down for cheeky cuts
Cheeky = design, not smaller cut. Use your normal hip-based size.
Measuring with padded bra
Skews bust 0.5–1 inch. Measure with non-padded or none.
Buying same brand year after year without remeasuring
Bodies change; suits stretch. Re-measure every 1–2 seasons.
FAQs
How are bikini tops sized?
S/M/L for A–C cups; band-cup for D+ (with structure).
What size bikini bottom?
Match hip measurement to brand chart.
Tops vs bra sizing?
Band-cup tops match bra system. S/M/L tops use bust-only conversion.
Should bikini fit tight when dry?
Snug, not tight. Stretches when wet.
Cheeky vs hipster vs brief?
Coverage difference, same hip-based sizing.
Do bikinis stretch over time?
Yes. Hand-wash, avoid hot tubs, cycle two suits.
Two Pieces, Two Right Numbers
For one-piece sizing see one-piece swimsuit measurement. For full bra-style sizing see bra band and cup measurement.
Selling bikinis on Shopify? Make D+ sizing visible.
Tailor Size Guide adds band-cup matching to every bikini top with cup sizing — and S/M/L matching for everything else.