Swimwear Guides / Size & Fit
How should a performance swimsuit fit?
Close enough to move as one with you. Comfortable enough that your breath, shoulders and attention remain free.
The short answer: a performance swimsuit should feel secure on dry land without pinching. In water it should stay smooth against the body, with no gaping, water pockets, slipping straps or restricted movement.
Measure before you choose
Use a soft tape over light clothing or underwear. Keep it level and relaxed: do not pull the tape tight enough to compress the body.
- Bust: around the fullest point.
- Underbust: directly beneath the bust.
- Waist: around your natural waist.
- Hip: around the fullest point of the seat.
- Height and weight: use these as supporting references, not as the only deciding measurements.
One-piece size guide
| Size | Height | Waist | Bust | Weight |
|---|---|---|---|---|
| S | 155–168 cm | 58–71 cm | 66–78 cm | 43–51 kg |
| M | 158–172 cm | 63–76 cm | 71–84 cm | 52–61 kg |
| L | 161–175 cm | 68–81 cm | 76–89 cm | 62–75 kg |
| XL | 169–178 cm | 76–90 cm | 85–95 cm | 75–90 kg |
Separates size guide
Tops
| Size | Length | Cup | Underbust | Weight |
|---|---|---|---|---|
| S | 28 cm | A–B | 64–76 cm | 43–51 kg |
| M | 29 cm | A–C | 69–81 cm | 52–61 kg |
| L | 30 cm | B–D | 77–89 cm | 62–75 kg |
| XL | 31 cm | C–E | 84–95 cm | 75–90 kg |
Bottoms
| Size | Waist | Hip | Weight |
|---|---|---|---|
| S | 53–68 cm | 66–78 cm | 43–51 kg |
| M | 58–73 cm | 71–84 cm | 52–61 kg |
| L | 66–81 cm | 76–89 cm | 62–75 kg |
| XL | 73–90 cm | 85–105 cm | 75–90 kg |
The five-movement fitting test
- Raise both arms overhead and rotate your shoulders.
- Take a deep breath: the underbust and neckline should remain secure without digging.
- Squat and bend forward; the bottom should stay in place.
- Twist from side to side and check for gaps at the neckline or underarm.
- Imagine the fabric wet: any loose pocket on dry land may collect water.
When you are between sizes
Start with the measurements that matter most to the style: torso and bust for a one-piece, underbust and cup for a top, waist and hip for a bottom. Some styles have specific advice. Gene has a close neck construction; choose your usual size for swimming or consider one size up for daily wear. Alma begins firmer at the waist and fuller upper bodies may prefer a size up. Bona runs more generously. Pona, Verda, Pura and selected Viva styles may be worn one size smaller for a more competitive training fit, but sizing down is not a universal rule.
Measurements are a starting point. Fabric stretch, torso length, preferred compression and the cut of each style all affect fit.
Size questions
Should a new swimsuit feel tight?
It should feel close and supportive, not painful. Red marks, restricted breathing, shoulder pressure or rolling edges indicate that the fit or style needs adjusting.
Should I size down because swimwear stretches in water?
Not automatically. Begin with the chart and the product-specific note. Size down only when you prefer a stronger training fit and the style guidance supports it.
Can I choose different sizes for tops and bottoms?
Yes. Separates are useful when your bust, waist and hip measurements sit in different size bands.