Swimming Suit Size Charts for Women, Men and Kids
The size charts behind swimwear labels: women's letter and numeric sizes, the numbered sizes on competitive suits, men's trunks, board shorts and jammers, and children's swimwear by age. Each chart lists the body measurements to compare against, in inches and centimeters.
Women's swimwear uses dress sizes: a medium is a US 8-10 and fits a 36.5-37.5 in (93-95 cm) bust and 38.5-39.5 in (98-100 cm) hip. Men's swim trunks use waist size: a medium fits a 31-33 in (79-84 cm) waist, and jammers and briefs are labeled with the waist in inches (a 32 fits a 32 in waist). Kids' swimwear follows age sizes, from 2T up to 14-16.
- Women's M
- US 8-10, UK 12-14
- Women's M bust
- 36.5-37.5 in
- Men's M waist
- 31-33 in (79-84 cm)
- Girls' XL
- 14-16
On this page
Women's swimsuit size chart
US swimwear follows women's dress sizes, with each letter covering two numbers. The bust governs one-pieces and tops; the hip governs bottoms. Measure over bare skin or a thin, unpadded bra.
| Letter | US | UK / AU | EU | Bust | Waist | Hip |
|---|---|---|---|---|---|---|
| XS | 0-2 | 4-6 | 32-34 | 32.5-33.5 in (83-85 cm) | 24.5-25.5 in (62-65 cm) | 34.5-35.5 in (88-90 cm) |
| S | 4-6 | 8-10 | 36-38 | 34.5-35.5 in (88-90 cm) | 26.5-27.5 in (67-70 cm) | 36.5-37.5 in (93-95 cm) |
| M | 8-10 | 12-14 | 40-42 | 36.5-37.5 in (93-95 cm) | 28.5-29.5 in (72-75 cm) | 38.5-39.5 in (98-100 cm) |
| L | 12-14 | 16-18 | 44-46 | 39-40.5 in (99-103 cm) | 31-32.5 in (79-83 cm) | 41-42.5 in (104-108 cm) |
| XL | 16-18 | 20-22 | 48-50 | 42-44 in (107-112 cm) | 34-36 in (86-91 cm) | 44-46 in (112-117 cm) |
| 1X | 14W-16W | 18-20 | 46-48 | 44-46 in (112-117 cm) | 36-38 in (91-97 cm) | 46-48 in (117-122 cm) |
| 2X | 18W-20W | 22-24 | 50-52 | 47-50 in (119-127 cm) | 39-42 in (99-107 cm) | 49-52 in (124-132 cm) |
Swim brands differ by about 1 in per measurement. Bikini tops sold by bra size (32C, 34DD and so on) follow bra charts instead; see the bra size guide. How each style should fit, including torso length for one-pieces, is in our swimsuit fit guide.
Numbered competitive sizes
Racing and training suits from competitive brands are often labeled 24 to 46 rather than with dress sizes. The numbers are not US sizes and differ between lines. On Speedo's Global Fit chart, a 30 is a UK 6 / US 2 (bust about 79-83 cm), a 32 is a UK 8 / US 4 (84-87 cm) and a 34 is a UK 10 / US 6 (88-92 cm), with each step of 2 adding one dress size. Competitive suits are cut to fit very snugly when dry, because the fabric relaxes in water and loose fabric creates drag.
Men's swimwear size chart
Men's swimwear is sized by waist. Trunks and board shorts often use letters; competitive styles use the waist in inches.
| Letter | Numbered size | Waist | Hip |
|---|---|---|---|
| S | 28-30 | 28-30 in (71-76 cm) | 35-37 in (89-94 cm) |
| M | 31-33 | 31-33 in (79-84 cm) | 38-40 in (97-102 cm) |
| L | 34-36 | 34-36 in (86-91 cm) | 41-43 in (104-109 cm) |
| XL | 37-40 | 37-40 in (94-102 cm) | 44-47 in (112-119 cm) |
| XXL | 41-44 | 41-44 in (104-112 cm) | 48-51 in (122-130 cm) |
Swim trunks have an elastic waist and drawcord, so they fit over a range of 3-4 in. Board shorts have a fixed waist with a lace-up fly and are best bought in your exact pant waist size. Inseam lengths for both are explained in the shorts inseam guide.
Jammers, briefs and square-legs
| Size label | Waist | Fit notes |
|---|---|---|
| 26 | 26 in (66 cm) | Also used for teen boys |
| 28 | 28 in (71 cm) | |
| 30 | 30 in (76 cm) | |
| 32 | 32 in (81 cm) | Most common adult size |
| 34 | 34 in (86 cm) | |
| 36 | 36 in (91 cm) | |
| 38-40 | 38-40 in (97-102 cm) |
Jammers reach to just above the knee and briefs sit at the hip, but both use the same waist number. Training suits are bought at your waist size; tech racing suits are designed to be very tight and are usually chosen by the manufacturer's height and weight chart, often a size down from training suits.
Kids' swimsuit size chart
Children's swimwear uses age sizes. Check height first, since a tall child needs a longer one-piece even if the chest fits the smaller size.
| Size | Typical age | Height | Chest |
|---|---|---|---|
| 2T | 2 years | 33-36 in (84-91 cm) | 20-21 in (51-53 cm) |
| 3T | 3 years | 36-39 in (91-99 cm) | 21-22 in (53-56 cm) |
| 4T | 4 years | 39-41 in (99-104 cm) | 22-23 in (56-58 cm) |
| XS (4-5) | 4-5 years | 41-44 in (104-112 cm) | 23-24 in (58-61 cm) |
| S (6-6X) | 6 years | 45-48 in (114-122 cm) | 24-25 in (61-64 cm) |
| M (7-8) | 7-8 years | 49-52 in (124-132 cm) | 26-27 in (66-69 cm) |
| L (10-12) | 9-11 years | 53-58 in (135-147 cm) | 28-30 in (71-76 cm) |
| XL (14-16) | 12-14 years | 59-63 in (150-160 cm) | 30-32 in (76-81 cm) |
Boys' trunks use the same age bands, with S, M and L often labeled 8, 10-12 and 14-16. Swim diapers for babies and toddlers are sized by weight, which varies by maker, so use the pack chart. European children's swimwear is labeled by height in centimeters (for example 116 or 128).
Buying a size ahead works for T-shirts but not swimwear. A loose one-piece fills with water and slides off the shoulders, and baggy trunks drag in the water. Buy the current size, or one size up only if the child is at the top of the range.
How to measure for swimwear
- Bust: around the fullest part, arms relaxed.
- Under-bust: snug, directly below the bust. Needed for bra-sized bikini tops.
- Waist: at the narrowest point for women, or where the waistband sits for men.
- Hip: around the fullest part of the seat, feet together.
- Torso loop (one-pieces): from the top of one shoulder, down the front, through the crotch and back up to the same shoulder.
If two measurements point to different sizes, use the bust for one-pieces and tops, the hip for bottoms, and the torso loop when a one-piece is a close call. Where to swim once the suit fits is another matter; pool dimensions are in our pool size guide, and sport-by-sport sizing for other kit is in the athletic wear size guide.
Frequently asked questions
Is a size 4 swimsuit a small or a medium?
A small. In US women's swimwear, XS covers sizes 0-2, S 4-6, M 8-10, L 12-14 and XL 16-18. A size 4 fits about a 34.5 in (88 cm) bust and 36.5 in (93 cm) hip.
What is a size 12 in swimsuits?
A US 12 is a large, equal to UK 16 and EU 44, for about a 39 in (99 cm) bust, 31 in (79 cm) waist and 41 in (104 cm) hip. A UK 12 is a US 8, which is a medium.
Is a swimsuit size XL an 18?
XL usually covers US 16-18 (UK 20-22). An 18 sits at the top of XL; if you are between XL and a plus size, compare your hip with the brand's chart, since some brands start 1X at 16W.
Is a size 32 swimsuit a 14?
No. Numbered sizes such as 28, 30 and 32 on competitive and European swimsuits are not US dress sizes. On Speedo's Global Fit chart, a 32 corresponds to a UK 8 / US 4 for a bust of about 84-87 cm (33-34 in). Other lines and brands differ, so check the bust range.
Can a girl wear boys' swim trunks?
Yes. Boys' trunks are sized by age or waist like girls' bottoms. Choose by waist and hip: a girl who wears girls' 10-12 usually fits boys' M (10-12) or L (14-16) if her hips are fuller, because boys' cuts have less room in the seat.
Is a girls' XL the same as a women's XS?
Close but not the same. Girls' XL (14-16) fits about a 30-32 in (76-81 cm) chest, while women's XS fits a 32.5-33.5 in (83-85 cm) bust with shaping for it. Teens who have developed a bust usually fit women's XS better.
What waist size is a medium in men's swimwear?
About 31-33 in (79-84 cm) in most brands, the same as men's shorts. Board shorts in a numbered size use the waist directly: 32 fits a 32 in waist.