Men's Swimwear Styles Explained: Briefs, Jockstraps, Trunks & G-Strings

Men's swimwear falls into four main families: briefs, jockstraps, trunks (including boardshorts and square cuts) and g-strings. Briefs and jockstraps offer the least coverage and the most support, trunks sit in the middle for everyday comfort, and g-strings give the most skin exposure for tanning, pool parties or festival wear.

Walk into any swim shop, or scroll through one online, and the range can feel bigger than it needs to be. Trunks, briefs, boardshorts, jammers, jockstraps and g-strings all do a slightly different job, and picking the wrong one usually means a suit that rides up, chafes, or just doesn't suit the occasion. This guide breaks down each style in plain English: where it came from, who it suits, what it's made of, and how to choose between them. We'll also look at fabric, fit and a few well known brands worth knowing before you buy.

Swim Briefs: The Classic Speedo Style

The swim brief is the low rise, snug fitting style most people picture when they hear the word Speedo, though Speedo is actually a brand name, not the garment itself. Speedo, founded in Sydney in 1914, introduced its first men's swim brief in the 1950s, and by the 1956 Melbourne Olympics the entire Australian swim team was wearing them on the way to eight gold medals. The design that became the modern brief, cut narrow at roughly 7.5 centimetres wide, was created by Speedo designer Peter Travis in 1959 and quickly became the dominant racing cut.

Briefs are built for one thing above all else: minimal drag in the water. Less fabric means less resistance, which is why competitive swimmers, divers and water polo players still choose them over almost anything else. Off the racing lane, briefs remain a popular choice for lap swimming, sunbaking and beach days for men who want a streamlined, supportive fit without extra material bunching up. In Australia, the style has picked up the cheeky nickname budgie smugglers, a term that stuck so well an entire local swimwear label was later built around it.

If you're new to briefs, sizing runs snugger than trunks, so it pays to check a brand's own chart rather than guessing from your usual waist size. Our guide to how underwear and swimwear sizing works walks through measuring yourself properly, brand by brand.

Jockstraps: From Cycling Gear to Swimwear Staple

The jockstrap has one of the more unexpected origin stories in menswear. It was invented in 1874 by C.F. Bennett, an employee of the Chicago sporting goods company Sharp & Smith, to protect bicycle jockeys, meaning delivery riders, as they bounced over Boston's cobblestone streets. Bennett later founded the Bike Web Company and patented an improved version in 1897, and the jockstrap went on to become standard gear across contact sports for the next century.

Its swimwear crossover is more recent. A swim jockstrap keeps the same basic shape as the sports version: a supportive front pouch held in place by elastic straps that leave the backside bare, but made from quick drying, chlorine tolerant fabric instead of cotton mesh. The open back design means excellent breathability and a bold, unmistakable silhouette, which is why the style is popular for pool parties, resort holidays and festival or Pride events rather than everyday lap swimming. Several swimwear brands carry their underwear pouch technology straight across into their swim ranges, so if you like the support of a jockstrap but want something a little more discreet for general beachwear, our men's underwear style guide is a good place to compare the two.

Trunks, Boardshorts & Square Cuts: The Everyday Options

For most men, swimwear means something in this middle category: more coverage than a brief, less commitment than a jockstrap, and comfortable enough to wear all day.

• Swim trunks are the most versatile option: a mesh lined short with an elastic or drawstring waist, usually finishing somewhere between a 5 inch and 9 inch inseam. They work equally well in the pool, at the beach or lounging by a resort pool, and dry fast thanks to their lightweight builds.

• Boardshorts are longer again, typically an 8 to 9 inch inseam, with a higher sitting waistband, a drawstring or button and zip closure, and no mesh liner. They're built for surfing and watersports, where the extra length protects the thighs from chafing against a board, and their looser fit makes them the easiest style to wear straight off the beach and into a café.

• Square cut swimwear (sometimes called square leg or Euro cut) splits the difference between a brief and a jammer. It sits close to the body like a brief but has a straight horizontal hem across the upper thigh, giving a boxer brief style silhouette with a 3 to 5 centimetre inseam. It's a common choice for lap swimmers who want more thigh coverage than a brief without the knee length compression of a jammer.

G-Strings & Thongs: Maximum Tan, Minimum Fabric

At the opposite end of the coverage scale from boardshorts is the g-string, sometimes called a swim thong. This style uses a narrow triangle or pouch at the front, connected by a thin strap at the back, and it's designed for one purpose: sunbaking and pool lounging with as little tan line as possible.

G-strings are a niche style, and where you can actually wear one varies enormously. Many public beaches and pools have decency guidelines that rule them out, while other destinations, including parts of the Mediterranean, South America and dedicated resort or clothing optional beaches, treat them as completely normal beachwear. In Australia and much of the APAC region, the g-string is most at home at gay resorts, pool parties, and Pride or festival events, where it's worn as much for style and confidence as for tanning. Planning an outfit for one of those occasions? Our guide covering what to wear to a Pride parade or festival has more ideas.

Fabric choice matters more here than with any other style, since there's so little of it doing the job. Look for a soft, non chafing waistband and a fully lined pouch, since cheap fabric on a g-string tends to show its flaws fast.

A Quick Guide to Swimwear Fabric

Whatever style you land on, the fabric underneath it does most of the practical work. The three main players are:

• Nylon: soft, lightweight and comfortable, but it breaks down faster when exposed to chlorine over time, so it suits occasional swimmers and beach days better than daily pool laps.

• Polyester: more durable and genuinely chlorine resistant, holding its colour and shape through repeated pool sessions, though it's slightly less stretchy than nylon.

• Spandex (elastane or Lycra): rarely used alone, but blended in at around 10 to 20 percent to give trunks and briefs their stretch and recovery.

Many higher end suits also blend in PBT (polybutylene terephthalate), a stretchy, chlorine resistant polyester variant that's become popular in both competition and premium recreational swimwear for its durability. If you're a regular pool swimmer, a polyester or polyester PBT blend will outlast a plain nylon spandex suit many times over, and our swimwear fabric guide runs through the full comparison.

Sun exposure is worth thinking about too. Swimwear sold in Australia is sometimes tested against the AS/NZS 4399 sun protective clothing standard and given an Ultraviolet Protection Factor (UPF) rating, with 50+ marking the highest protection tier available. It's a handy detail to check if you spend long hours outdoors rather than in the water.

Getting the Fit Right

A swimsuit that's too loose will drag in the water and possibly slip off during a wave. One that's too tight will roll, dig in, or restrict movement. A few basics apply across every style covered above:

• Briefs and square cuts should sit snug against the body with no gaping at the leg openings.

• Trunks and boardshorts should sit comfortably at or just below the hip, with enough room to move without excess bunching.

• Jockstraps and g-strings rely on the waistband and straps for support, so check that these don't dig in or roll after a few minutes of movement.

Sizing varies noticeably between brands, so a medium in one label can fit like a small in another. It's worth checking the specific size chart before you buy rather than assuming your usual size will carry across, and our underwear and swimwear sizing guide explains why this happens and how to measure yourself accurately at home.

What About Padded or Enhancing Swim Briefs?

Some briefs, square cuts and jockstraps include a shaped or lightly padded front pouch, designed to give a more defined silhouette rather than dramatically change your shape. Done well, the effect looks natural rather than obvious, more a design detail than a costume piece. We've gone into how these pouches actually work, and whether they look convincing in real life, in our guide on padded and enhancing swimwear.

Best Men's Swimwear Brands to Know

A handful of brands have shaped men's swimwear as we know it today, and each tends to specialise in a slightly different style:

• Speedo: The Australian brand that invented the modern swim brief in the 1950s and remains the benchmark for competitive swimwear, still worn by Olympic swimmers today.

• aussieBum: Founded in Australia in 2001 by Sean Ashby, aussieBum built its name on the classic nylon brief cut and has since expanded into trunks, boardshorts and underwear, exporting to more than 70 countries.

• Budgy Smuggler: Started as a joke among friends in Sydney in 2003, this Australian label leaned straight into the local slang for brief style swimwear and now manufactures all of its Speedo style briefs and trunks in Australia.

• Cocksox: An Australian underwear and swimwear label launched in 2006, known for its supportive front pouch design that carries across everyday underwear, thongs and a full range of swim briefs, shorts and Brazilian cuts.

• Supawear: A contemporary label offering technical underwear and swimwear with a supportive pouch design, popular for its everyday to beach versatility.

Most of these labels sit together in our men's swimwear collection, which is worth a browse if you want to compare cuts and fabrics side by side before deciding.

Caring for Your Swimwear

Good swimwear lasts a lot longer with a small amount of care. Rinse it in cold water straight after every wear to remove chlorine, salt and sunscreen residue, then hand wash it in a mild detergent rather than tossing it in the washing machine, which can stretch or snag delicate fabric blends. Skip the tumble dryer altogether, since heat is one of the fastest ways to break down elastane and cause colours to fade. Instead, gently press out excess water, lay the suit flat in the shade, and let it air dry naturally.

Wearing Swimwear Beyond the Beach

Boardshorts and casual trunks have become genuinely dual purpose over the past decade, moving easily from the pool to a beachside lunch without anyone batting an eyelid. Briefs, jockstraps and g-strings are a different story: they're built and styled specifically for water, sunbaking or events, and are best kept to those settings. Curious which of your swimwear pieces can pull double duty as streetwear? Our guide on wearing swimwear as everyday clothing covers exactly where that line sits.

Frequently Asked Questions

What's the most comfortable men's swimwear style for everyday beach use?

For most men, swim trunks are the easiest everyday option. They offer a mesh lining for support, a relaxed elastic or drawstring waist, and enough coverage to move comfortably between the water, the sand and a café table without needing to change.

Are swim briefs still popular, or are they old fashioned?

Briefs never really went away. They remain the standard for competitive swimming and lap training because of their minimal drag, and they've had a genuine style resurgence in recent years among men who prefer a streamlined, low coverage look for the beach or pool.

Can I wear a jockstrap or g-string at a public beach?

It depends entirely on the beach and the country. Some public beaches and pools have decency guidelines that rule out very minimal styles, while others, including many resort, gay friendly and clothing optional beaches, are far more relaxed. When in doubt, check local rules before you head out, or save the style for a pool party, resort stay or Pride event.

What fabric lasts longest in a chlorinated pool?

Polyester and polyester PBT blends are the most chlorine resistant options and will outlast a plain nylon spandex suit if you swim laps regularly. Nylon spandex blends are softer and more comfortable but are better suited to occasional swims than daily pool sessions.

How do I know what size swimwear to buy?

Always check the specific brand's size chart rather than relying on your usual clothing size, since fit varies noticeably between labels. Measuring your waist and hip with a soft tape measure, then comparing those numbers to the brand's chart, is the most reliable way to get it right the first time.

Whichever style you land on, the goal is the same: something that fits properly, suits the occasion, and holds up to salt, sun and chlorine. For the full picture across men's and women's styles, fabrics and fit, head back to our complete swimwear style guide, or go ahead and shop men's swimwear to find your next pair.