Standing in front of a rack of men's swimwear, most guys narrow the choice down to two shapes: the swim brief and the swim trunk. Both work at the pool and on the beach, both come in endless prints, and both can look great. The difference is mostly about coverage, movement and how you plan to spend your day by the water. This guide walks through what separates the two, who each one suits, and how to pick the right size so your new swimwear actually stays put.
What is a swim brief?
A swim brief is the classic triangle-cut swimsuit. The leg opening rises up toward the hip, the side is narrow, and the back offers moderate coverage. In some countries people still call any swim brief a "speedo", after the brand that made the style famous for competitive swimming.
Because there is so little fabric, a swim brief does not drag in the water, does not bunch under you on a sun lounger and leaves almost no tan line on the thigh. It is the most practical shape if you swim laps, dive, or simply want the freedom of a cut that disappears once you are wet.
Swim briefs are also where designers have the most fun with prints. In the UPRO range you will find lemon graphics on stripes, botanical prints, shells and marine motifs — browse the full men's swim briefs collection to compare them side by side.
What are square-cut swim trunks?
Square-cut swim trunks — sometimes called square-leg trunks or "aquashorts" — keep the close, stretchy fit of a brief but cut straight across the upper thigh instead of angling up to the hip. The result is a short leg of fabric that covers more of the thigh and hips while still staying sleek in the water.
It is worth being clear about terms. In the US, "swim trunks" often means loose swim shorts or board shorts. In this guide, trunks means the fitted square-cut style: snug like a brief, but with more coverage. If you want a loose short that reaches toward the knee, that is a different category altogether.
Square-cut trunks are a good middle ground for men who like a tailored look but are not quite ready for the high leg of a brief. See the current styles in our men's square-cut swim trunks collection.
Swim briefs vs swim trunks at a glance
- Coverage: briefs show more thigh and hip; square-cut trunks cover the upper thigh.
- Movement: both are fitted and stretchy; briefs have the least fabric, so they feel the most unrestricted when swimming.
- Look: briefs read sporty and European-beach; square-cut trunks read tailored and slightly more classic.
- Tan lines: briefs leave a higher, smaller tan line; trunks leave a straight line across the thigh.
- Versatility: trunks are easier to wear for longer days around the pool with friends; briefs are ideal for laps, sunbathing and holidays where they are common.
How to choose: five practical questions
1. What will you actually do in the water?
If you swim lengths, snorkel or dive, the minimal shape of a swim brief is hard to beat. If you mostly relax, play in the shallows and move between the pool and the bar, either style works, and comfort with coverage becomes the deciding factor.
2. Where are you going?
Swim briefs are everyday beachwear across much of Europe, South America and Australia. At a resort, a beach club or a family pool, square-cut trunks can feel like the safer middle option. There is no rule here — but if you are unsure, packing one of each covers every situation.
3. How much coverage do you want?
Be honest about what makes you comfortable. Confidence matters more than the cut. If a higher leg makes you self-conscious, you will enjoy a square-cut trunk more. If you love the freedom of less fabric, go brief.
4. What suits your build?
A swim brief tends to make the legs look longer, which works well for shorter or slimmer frames. Square-cut trunks balance broader hips and muscular thighs because the straight line across the leg adds visual structure. These are guidelines, not limits — plenty of men break them and look great.
5. Bold print or clean solid?
A statement print is easier to wear on a smaller garment, which is why prints are so popular on swim briefs. Our Blue Stripe Lemon Swim Brief and Pink Stripe Lemon Swim Brief are good examples: a simple stripe up front and a playful lemon graphic at the back. For something more botanical, try the Stephania Plant Print Swim Brief. If you want a print with a little more coverage, the Narcissus Print Swim Trunks and the American Stripe Square-Cut Swim Trunks bring the same energy in a square-cut shape.
Can't decide? Pair them up
Some UPRO prints come in both shapes. The Narcissus print, for example, is available as the Narcissus Print Swim Brief and as square-cut trunks, so you can try both silhouettes in the same design. Likewise, the yellow pinstripe American Stripe Triangle Swim Brief has a square-cut twin. Wear the brief for swimming and the trunks for a long lunch by the pool.
Want two looks in one? The Tie-Side Reversible Swim Brief has two printed faces and adjustable side ties, which also makes it easy to fine-tune the fit.
Getting the size right
Fitted swimwear only works when it fits. A swim brief or square-cut trunk that is too loose can slip when you dive in; one that is too tight will dig in at the waist and the leg.
- Measure around the point where the waistband will sit — usually just above the hip bones — rather than your trouser waist.
- Compare that number with the size chart on each product page. Every UPRO swim style is offered in sizes M to XXL.
- If you are between sizes and plan to swim actively, the smaller size usually stays more secure; if you prefer a relaxed feel, size up.
- Check the drawstring or ties where available and adjust them before you get in the water.
Our fit and size guide explains how to measure step by step.
Caring for your swimwear
Chlorine, salt, sunscreen and heat all wear down stretch fabric over time. Rinse your swimwear in cool fresh water as soon as you can after swimming, wash it gently by hand, and dry it flat in the shade rather than in a tumble dryer or direct sun. Rotating two pieces over a holiday also gives each one time to recover its shape.
FAQ
Are swim briefs and speedos the same thing?
Mostly, yes. "Speedo" is a brand name that became shorthand for the triangle-cut swim brief. Today many brands make swim briefs in that shape.
Are square-cut swim trunks the same as swim shorts?
No. Square-cut trunks are fitted and stretchy with a short leg, while swim shorts and board shorts are looser and longer.
Which is better for swimming laps?
A swim brief, because it has the least fabric and creates the least drag. Fitted square-cut trunks are also comfortable for swimming.
Should I size up or down in swimwear?
Start with the size chart. If you are between sizes, choose the smaller one for active swimming and the larger one for comfort and lounging.
Can I wear a swim brief if I'm not used to them?
Absolutely. If you want to ease in, start with square-cut trunks, or pick a swim brief with a slightly more moderate cut and a print you love.
Ready to choose? Browse all men's swimwear from UPRO — swim briefs from $34.90, square-cut trunks from $34.90, sizes M–XXL, each piece sold individually.