FIND YOUR PERFECT FIT
Size Guides
Find your size across tops, bottoms, and one-pieces.
For the most accurate fit, select “Find your size” on each product page, located near the size selection. This will open more detailed guidance.
If you need additional help, please email us at customerservice@siennaswim.com
TOPS
For cup size and coverage guidance, use “Find your size” on each product page.
| Size | US | Bust (in) | Waist (in) |
|---|---|---|---|
| XS | 0–2 | 31–33 | 23–25 |
| S | 4–6 | 33–35 | 25–27 |
| M | 8–10 | 35–37.5 | 27–29 |
| L | 12–14 | 37.5–40 | 29–31 |
| XL | 14–16 | 40–42.5 | 31–34 |
| XXL | 16–18 | 42.5–45 | 34–37 |
| 2XL | 18–20 | 45–48 | 37–40 |
| 3XL | 20–22 | 48–51 | 40–43 |
BOTTOMS
For coverage and fit by style, use “Find your size” on each product page.
| Size | US | Waist (in) | Hips (in) |
|---|---|---|---|
| XS | 0–2 | 23–25 | 33–35 |
| S | 4–6 | 25–27 | 35–37 |
| M | 8–10 | 27–29.5 | 37–39.5 |
| L | 12–14 | 29.5–32 | 39.5–42.5 |
| XL | 14–16 | 32–35 | 42.5–45.5 |
| XXL | 16–18 | 35–38 | 45.5–48.5 |
| 2XL | 18–20 | 38–41 | 48.5–51.5 |
| 3XL | 20–22 | 41–44 | 51.5–54.5 |
ONE PIECES
For support and fit details by style, use “Find your size” on each product page.
| Size | US | Bust (in) | Waist (in) | Hips (in) |
|---|---|---|---|---|
| XS | 0–2 | 31–33 | 23–25 | 33–35 |
| S | 4–6 | 33–35 | 25–27 | 35–37 |
| M | 8–10 | 35–37.5 | 27–29.5 | 37–39.5 |
| L | 12–14 | 37.5–40 | 29.5–32 | 39.5–42.5 |
| XL | 14–16 | 40–42.5 | 32–35 | 42.5–45.5 |
| XXL | 16–18 | 42.5–45 | 35–38 | 45.5–48.5 |
| 2XL | 18–20 | 45–48 | 38–41 | 48.5–51.5 |
| 3XL | 20–22 | 48–51 | 41–44 | 51.5–54.5 |
HOW TO MEASURE
Use these measurements as a guide when selecting your size.