The answer depends on which brand or country you ask.
Part of the confusion comes from what appears to be different brands defining their cuts inconsistently, but it may come down to the brand’s country of origin. Here in Australia and the United Kingdom what we commonly refer to as trunks the American equivalent is called a boxer brief. The difference here is only terminology.
You can see this taking place online particularly in stores carrying multiple brands from Australia, UK and the US, where you can see the discrepancies for what is effectively the same fit/style underwear.
Easy enough right?
That’s until an American shorter leg version of the boxer brief was introduced and they also named this a “trunk”, adding further confusion to underwear shoppers. It can become overwhelming especially if you’re after a particular leg length. Just keep in mind that an American trunk is effectively shorter and not the same as the Australian version of the trunk.
So whats a short legged version of a trunk in Australia you ask? We would call it a short trunk and long trunk for the longer leg version.
To simplify your shopping experience just keep and eye out visually for the length of leg that suits you rather than the term used if your not familiar with a particular brand. It also helps if the underwear is shown worn by a model, if not simply ask for the inseam or measurement of the side length and measure it against your body to know approximately how far down the leg it will sit on you.
So there you have it! Hopefully you’re now well equipped with the knowledge on how to shop the difference between the two styles when shopping online and always get the right fit.