Briefs, Boxers, Boxer Briefs or Trunks: How to Choose
The five types of men's underwear, and a way to choose between them based on your trousers, your thighs and your day rather than a flatmate's opinion.
The Trunk Is the Sweet Spot
Shorter than a boxer brief, more covered than a brief, and quietly the right answer for a lot of men who have never tried one. The case for the trunk.
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There is a style sitting in the middle of the drawer that almost nobody arrives at deliberately. Men end up in briefs because they always were, or in boxer briefs because everyone is, or in loose boxers because of something that happened to British advertising in 1985 Launderette: The Sixty Seconds That Rewrote Men's Underwear. Very few men end up in trunks on purpose. They buy a pair by accident in a three-pack, wear it, and then spend a year wondering why that one was better.
The trunk is a brief with a short square leg, usually two to four centimetres of thigh, cut squarer through the seat than a brief and stopping well above where a boxer brief stops. That description makes it sound like a compromise, and compromise is a word that has done the garment no favours at all. It is not the average of two other things. It is the one style that fixes the specific problem each of the others has.
What it actually solves
Take the two complaints that come up most often in this whole subject.
Men who dislike briefs mostly dislike exposure. Not the support, not the shape under trousers, but the amount of leg and hip on show in a changing room, in a hotel corridor, in front of somebody new. Whether that is rational is a separate conversation and this site has had it at length The Locker Room Question: Getting Over the Fear of Being Seen in Briefs. It is also beside the point, because the trunk gives you the brief's entire engineering with a leg on it, and the objection evaporates.
Men who dislike boxer briefs mostly dislike fabric. Too warm in July, too much in a bag, too visible under a light summer trouser, too much leg to ride up. A trunk removes roughly half the leg and every one of those complaints goes with it.
Same garment, two different rescues. That is an unusual thing for a piece of clothing to manage.
The tailoring argument
This is where the trunk quietly wins and hardly anyone notices.
A boxer brief hem lands in the middle of the thigh, which is the exact place a slim or lightweight trouser starts to skim the leg. In a dark heavy trouser you get away with it. In a pale linen, a summer suit, or anything cut close, the hem draws a horizontal line across the leg that is visible from further away than men think.
A trunk hem sits high enough that the trouser has not yet made contact, so there is nothing to see. You get the coverage without the line. For a wedding, a summer suit or anything photographed, this is a real advantage over the style most men would default to Under the Suit: What to Wear on Your Wedding Day.
The same logic applies to shorts. A boxer brief hem and a summer short hem land within a few centimetres of each other, which is why so many men who are perfectly happy eleven months of the year get caught out in the twelfth Briefs, Boxers, Boxer Briefs or Trunks: How to Choose.
Where it does not win
Honesty first. The trunk does not solve chafing. If your thighs touch when you walk any real distance, you need a leg that reaches past the widest part of the thigh, and a trunk does not reach it. No fabric on earth changes that. This is the one situation where the boxer brief is not a preference but the correct tool The Boxer Brief Won, and It Deserved To.
It is also not the coolest thing in the drawer. A brief is lighter, dries faster and packs smaller, so for the hottest weeks of the year and for travelling with one bag the brief still wins on the numbers Travel Light: The One-Bag Case for Briefs.
And it is not a sports garment in the way a long-legged compression short is. It will get you through a gym session comfortably enough. It will not get you through a hundred kilometres on a bike.
What is left after those three exceptions is most days, for most men, doing most things. Which is a fairly large claim for a garment nobody chooses on purpose.
How it should fit
The waistband sits on the hip bone, level, staying put on the stairs. Nothing new there.
The leg lies flat against the thigh with no gape at the outer edge when you sit. A trunk leg is short enough that it sits above the widest part of the thigh by design, so it will not creep the way an underlength boxer brief creeps, but a leg cut too wide will flare and show under a trouser.
The seat is where the trunk differs most from a brief, and it is the thing to check in a mirror. A proper trunk is cut square across the back with a defined seat panel, not simply a brief with a hem extension. A cheap trunk skips the seat shaping, which is why cheap trunks pull when you sit and better ones do not.
The rise is worth a thought. Most trunks are cut lower than a classic brief, which suits low-rise trousers and does not suit anything with a proper high waist. If you wear trousers that sit at the natural waist, look for a mid-rise trunk rather than the standard one How a Brief Should Actually Fit.
What to buy
Cotton with a few percent elastane is the everyday default and the one to start with, because a trunk lives or dies on shape retention and cotton without stretch will not hold a square leg cotton stretch trunk.
Modal is the upgrade that people notice immediately. Softer, closer, better under tailoring, and the fabric that makes the strongest argument for the style at all modal trunk.
Look at the leg hem before you look at anything else. A flat, wide, well-finished hem stays where it is. A thin rolled hem on a stretchy fabric will rope within a month, and roping at the top of the thigh is uncomfortable in a way that will put you off the whole style for the wrong reason.
Buy two pairs before you buy eight. Trunk sizing varies more between brands than brief sizing does, because the leg length and the rise are both moving at once. The makers who get the seat panel and the hem right are a shorter list than the shelf suggests The Best Trunks You Can Actually Buy.
The quiet recommendation
If you are wearing boxer briefs and you have never once thought about it, carry on. Nothing here is an instruction.
But if there is a nagging thing, if it is too warm in summer, or the hem shows under your good trousers, or you have started reading about briefs and cannot quite bring yourself to it, the trunk is sitting right there and it costs one pair to find out. It is the closest thing this subject has to a garment with no argument against it, which may be precisely why it never gets talked about.
Questions people ask
What is the difference between trunks and boxer briefs?
Leg length and cut. A trunk has a short square leg of roughly two to four centimetres and stops above the widest part of the thigh. A boxer brief carries the leg down the thigh, typically fourteen to twenty centimetres. Trunks are also usually cut squarer through the seat and lower in the rise. The practical difference is that trunks run cooler and sit better under slim trousers, while boxer briefs stay put better and are the only one of the two that prevents chafing.
Are trunks better than briefs?
Not better, more covered. A trunk gives you the same support and the same shape under clothes with a short leg added, which costs you a little breathability and a little packed volume and buys you a garment most men feel more comfortable being seen in. If neither of those matters to you, the brief is lighter and there is no reason to change.
Do trunks ride up?
Far less than a badly fitted boxer brief, because the leg is cut to sit above the point where the thigh widens rather than fighting it. If a trunk does move, the usual cause is a leg opening cut too wide or a thin hem that has lost its shape.
Can you wear trunks under a suit?
Yes, and they are arguably the best choice for it. The hem sits above the point where a slim trouser starts to touch the leg, so there is no visible line, and the square seat keeps everything flat through the back. In a pale suit, choose a skin-tone rather than a white pair Briefs for the Office: The Tailoring Argument.