Nike Mens Swimwear Size Guide

This size guide covers Nike Men's Swimwear. Nike splits its men's swimwear into two distinct categories: Performance Training — high-compression briefs, jammers, and square legs built for lap swimming — and Casual Lifestyle — loose-fitting volley shorts and boardshorts designed for poolside and beach wear. Choosing between them depends on whether you are tracking lap times or lounging poolside.

Select your size using your waist (A) and hip (B) measurements. All measurements are body measurements taken directly against the skin.

Shop Nike Men's Swimwear →

Body Measurement Points

How to Measure

Take all measurements directly against your skin using a soft tape measure. Wear minimal clothing and keep the tape horizontal and level for each measurement.

A
WaistMeasure around the narrowest part of your natural waist, keeping the tape horizontal and level.
B
HipsMeasure around the fullest part of your hips and seat, keeping the tape horizontal.

If your measurements fall between sizes, speak to a member of staff at Allens who will be happy to advise on the best fit.

Training vs. Casual — Which Style Is Right for You?

Feature	Nike Performance Training	Nike Casual Lifestyle
Primary Cut	Skin-tight briefs, jammers, and square legs	Loose volley shorts and boardshorts
Material	HydraStrong polyester/PBT fabric blend	Quick-drying 100% woven polyester
Lining	Minimal front lining for opacity	Built-in interior mesh briefs for support
Pockets	Zero pockets to eliminate drag	Deep side pockets with mesh drainage

Sizing Table — Nike Men's Swimwear

Sizes 20 – 30

Size	20	22	24 (XS)	26 (S)	28 (S)	30 (M)
Body Measurements (cm)
A — Waist	53.5–58.5	58.5–63.5	63.5–68.5	68.5–73.5	73.5–78.5	78.5–84
B — Hips	63.5–68.5	68.5–73.5	78.5–84	84–89	89–94	94–99
Body Measurements (inches)
A — Waist	21–23	23–25	25–27	27–29	29–31	31–33
B — Hips	25–27	27–29	31–33	33–35	35–37	37–39

Sizes 32 – 42

Size	32 (M)	34 (L)	36 (XL)	38 (XL)	40 (XXL)	42 (XXL)
Body Measurements (cm)
A — Waist	84–89	89–94	94–99	99–104	104–109	109–114
B — Hips	99–104	104–109	109–114.5	114.5–119.5	119.5–124.5	124.5–129.5
Body Measurements (inches)
A — Waist	33–35	35–37	37–39	39–41	41–43	43–45
B — Hips	39–41	41–43	43–45	45–47	47–49	49–51

All measurements are body measurements, not garment measurements. If your measurements fall between sizes, speak to a member of staff at Allens who will be happy to advise.

Fit Notes — Nike Men's Swimwear

Use your waist measurement (A) as the primary guide — this is the most reliable indicator of fit across both training and casual styles.
For performance training styles (briefs, jammers, square legs) — the suit should feel compressive and snug with no sagging or wrinkling. If between sizes, size down for a tighter fit or up for more comfort.
For casual lifestyle styles (volley shorts, boardshorts) — the waistband should sit comfortably at the natural waist. The fit is intentionally loose through the leg.
If your waist and hip measurements suggest different sizes, size for the waist on training suits and for the hip on casual shorts for the most comfortable fit.
Nike's HydraStrong fabric (used in training styles) resists chlorine, sun fade, and loss of stretch over time — rinse in cold fresh water after every pool session.
Nike's casual lifestyle shorts use quick-drying woven polyester with built-in mesh briefs and deep side pockets with drainage — not suitable for competitive swimming.
Unsure? Contact our team or call +44 1827 330600. Speak to a member of staff at Allens if you are unsure.

Frequently Asked Questions — Nike Men's Swimwear

Measure your waist (A) and hips (B) using a soft tape measure taken directly against your skin. Use your waist measurement as the primary guide and compare to the sizing table above. If your measurements fall between sizes, speak to a member of staff at Allens who will be happy to advise.

Nike performance training swimwear — briefs, jammers, and square legs — uses HydraStrong polyester/PBT fabric with a skin-tight, compressive fit and zero pockets to eliminate drag. Nike casual lifestyle swimwear — volley shorts and boardshorts — uses quick-drying woven polyester with a loose fit, built-in mesh briefs, and deep side pockets. Choose training styles for lap swimming and casual styles for poolside or beach use.

If your measurements fall between two sizes, the best choice depends on the style. For training suits, size down for a tighter, more performance-oriented fit or up for more comfort during longer sessions. For casual shorts, size for comfort at the waist. Speak to a member of staff at Allens who will be happy to advise based on the specific style you are considering.

Nike casual lifestyle shorts are not designed for lap swimming. The loose fit and woven polyester fabric create drag in the water and the deep pockets fill with water during swimming. For pool training, choose a Nike performance training style — briefs, jammers, or square legs — which are specifically engineered to minimise drag and withstand regular chlorine exposure.

Nike HydraStrong is a performance fabric made from a polyester and PBT blend specifically engineered for frequent pool use. It resists chlorine degradation, sun fading, and loss of stretch over time — meaning the suit retains its shape and coverage session after session. HydraStrong is used across Nike's training swimwear range including briefs, jammers, and square legs.

Briefs offer the least resistance and maximum freedom of movement — popular with competitive swimmers and triathletes. Jammers extend to just above the knee and provide light muscular compression and coverage — a popular choice for training. Square legs sit mid-thigh and offer a balance between coverage and mobility. All three use the same sizing — choose based on your personal preference and the type of training you do.

For training styles: rinse in cold fresh water immediately after every pool session to remove chlorine. Hand wash or machine wash on a gentle cycle at 30°C. Do not tumble dry, iron, or dry-clean. Dry flat away from direct sunlight. For casual styles: follow the care label on the individual garment — most can be machine washed. Avoid fabric softeners on training styles as they reduce the fabric's performance properties.

Nike training swimwear is designed for a close, compressive fit — it will feel tighter than everyday clothing at the same waist measurement. The sizing table above uses body measurements, so comparing your actual waist measurement to the table will give the most accurate result. If you prefer a less compressive feel, consider sizing up. For casual styles, the fit is intentionally loose and relaxed. Speak to a member of staff at Allens if you are unsure.