A swimsuit has to fit closely, stay put when you move and lose very little shape when wet. For women a one-piece needs one more measurement than other clothes, the torso length. This calculator takes your measurements and returns the swimsuit size from Nike’s charts: top, bottom and one-piece for women, and swim shorts or trunks for men.
How to use the swimsuit size calculator
- Choose women’s or men’s sizing.
- Measure the bust or chest (fullest part), waist (narrowest part) and hips (fullest part), tape horizontal.
- For a one-piece, measure the torso: from the high point of the shoulder over the bust, through the legs and up the back.
- Enter the measurements in inches or centimetres and read the sizes.
Swimsuit size formula (chart lookup)
one-piece = the largest of the bust, hip and torso sizes
between sizes → the larger size
The charts are Nike’s women’s and men’s swimsuit size charts (retrieved 2026-10-15). Women’s sizes run XS to 2XL, with a plus range of 1X to 3X; men’s sizes run XS to 4XL. A measurement on the upper limit of a range belongs to that size. The one-piece rule is a safe-choice rule of this page, not Nike’s.
Women
| Size | US | Bust (in) | Waist (in) | Hip (in) | Torso (in) |
|---|---|---|---|---|---|
| XS | 0–2 | 31.5 – 33.5 | 24 – 26 | 34.5 – 36.5 | 55 – 57.75 |
| S | 4–6 | 33.5 – 35.5 | 26 – 28 | 36.5 – 38.5 | 57.75 – 60.5 |
| M | 8–10 | 35.5 – 37.5 | 28 – 30 | 38.5 – 40.5 | 60.5 – 63.25 |
| L | 12–14 | 37.5 – 40.5 | 30 – 33 | 40.5 – 43.5 | 63.25 – 66 |
| XL | 16–18 | 40.5 – 43.5 | 33 – 36 | 43.5 – 46.5 | 66 – 68.5 |
| 2XL | 20–22 | 43.5 – 46.5 | 36 – 39 | 46.5 – 49.5 | 68.5 – 70.25 |
| 1X | 16W–18W | 44 – 48 | 38 – 42 | 47 – 51 | 68 – 69.75 |
| 2X | 20W–22W | 48 – 52 | 42 – 46 | 51 – 55 | 69.75 – 71.5 |
| 3X | 24W–26W | 52 – 56 | 46 – 50 | 55 – 59 | 71.5 – 73.25 |
Men
| Size | Chest (in) | Waist (in) | Hip (in) |
|---|---|---|---|
| XS | 32.5 – 35.5 | 26 – 29 | 32 – 35 |
| S | 35.5 – 38.5 | 29 – 32 | 35 – 38 |
| M | 38.5 – 41.5 | 32 – 35 | 38 – 41 |
| L | 41.5 – 44.5 | 35 – 38 | 41 – 44 |
| XL | 44.5 – 47.5 | 38 – 41 | 44 – 47 |
| XXL | 47.5 – 51 | 41 – 44 | 47 – 50 |
| 3XL | 51 – 54 | 44 – 47 | 50 – 53 |
| 4XL | 54 – 57 | 47 – 50 | 53 – 55 |
Worked example
A woman measures bust 36 in, waist 29 in, hips 39 in and torso 61 in.
- Bust 36 → M; waist 29 → M; hips 39 → M.
- Torso 61 in falls in the 60.5–63.25 in range → M, so the one-piece is M (US 8–10).
Choosing swimwear
- Mix and match: separates let you pick a top and a bottom size independently.
- Torso length matters for one-pieces: a suit that is too short pulls on the shoulders.
- Fabric: chlorine and sun wear down stretch, so a fit that feels very tight when dry may be right.
- Support: for larger busts, bra-sized swimwear gives more support than letter sizes (see the Bikini Top Size Calculator).
For dresses and other clothing see the Dress Size Calculator and Pants / Trouser Size Calculator. This page gives general sizing information from published charts.
Sources
Every figure above comes from these pages, read directly on the dates shown. Brand names are used only to identify published charts.
- Nike — women’s swimsuit size chart (bust, waist, hip, torso) — checked 2026-10-15
- Nike — men’s swimsuit size chart (chest, waist, hip) — checked 2026-10-15
Frequently asked questions
How do I choose a swimsuit size?
Measure bust, waist and hips (and the torso for a one-piece) and compare them with the chart. Nike says that if hips and waist point to different sizes you should order the size indicated by your hips.
What is the torso measurement?
It is a length: from the high point of the shoulder over the fullest part of the bust, down through the legs and up the back to the start. It decides whether a one-piece will be long enough.
Which size is best for a one-piece?
Nike does not give a single rule. The calculator suggests the largest of the bust, hip and torso sizes, because a one-piece must fit at every point. Swimwear stretches, so a close fit is normal.
What if I am between sizes?
Nike advises the smaller size for a tighter fit and the larger size for a looser fit. The calculator rounds up to the next chart value.
What about bikinis and bras?
For bra-sized or bikini tops see the Bikini Top Size Calculator. For swimming trunks, men use waist and hip. Convert S, M, L to numbers with Letter Size to Number Converter (S/M/L).