Ask a man his shoe size and he'll tell you instantly. Ask him his underwear size and you'll get a pause, a guess, and probably something based on whatever he grabbed last time at the store. "Medium, I think."
This isn't because men don't care. It's because the underwear industry has trained us to believe that fit doesn't matter — that S, M, L, and XL are close enough, and anything beyond that is overthinking it.
It's not overthinking it. It's undertaking it.
The cascading effects of bad fit
Too tight: Restriction, heat buildup, reduced circulation. The body's thermal regulation depends on airflow, and compressed fabric against the groin traps heat precisely where the body needs to dissipate it. Studies have shown that sustained elevated scrotal temperature — even by 1–2°C — can impact sperm quality. Beyond fertility, tight underwear contributes to fungal infections, skin irritation, and that constant, distracting discomfort you've learned to ignore.
Too loose: Bunching, riding, chafing. Without proper support, fabric migrates during movement. The inner thighs bear the brunt — constant friction between skin and shifting fabric leads to redness, rawness, and that end-of-day soreness that most men chalk up to "just walking a lot." It's not the walking. It's the underwear.
Wrong rise: The waistband sits too high or too low, spending the day slowly creeping toward its preferred position. You adjust. You adjust again. By 3 PM you've unconsciously adjusted your underwear 30 to 40 times. Each one a tiny interruption, a micro-distraction you didn't even register.
Why we built the sizing differently
KÖRPER doesn't size by shirt size or by weight range. We size by waist measurement in centimeters, because that's the only number that matters. Our size guide asks you to measure at the natural waist — the narrowest point above your hip bones — and gives you a precise recommendation.
We also design each style with a different fit profile. Our briefs are engineered for a snug, supportive fit. Our boxer briefs balance support with range of motion. Our trunks sit between the two. The same waist size might be a different experience across styles, and that's intentional — because what your body needs from underwear changes with what you're doing.
The adjustment test
Here's a simple diagnostic: count how many times you adjust your underwear tomorrow. Reach down, pull up, shift, tug — count every one. If the number is higher than zero, something isn't right.
Good underwear doesn't need adjusting. It doesn't ride. It doesn't bunch. It doesn't creep. It stays where you put it at 7 AM and it's still there at 11 PM. That's not a luxury. That's baseline functionality. And it starts with fit.
