The Erobold Guide
Most men size their underwear the way they size a T-shirt. That's the entire problem — and it's fixable in about ninety seconds.
Nobody grows up learning how to measure for this category. You default to whatever size you wear on top, or whatever the last brand called "Medium," and hope the elastic figures out the rest. Sometimes it does. Often it doesn't — and by the time you know, the fit's already decided how the piece feels for the next year.
This isn't a vanity guide. It's a ninety-second habit that means you never have to think about this again.
Why "My Usual Size" Doesn't Work Here
A T-shirt size is about your chest and shoulders. Underwear sizing is about your waist and, depending on the cut, how much room the pouch and leg opening actually need — two measurements that don't scale together the way brands assume they do. Two men who both wear a Large in shirts can need completely different sizes in a jockstrap, because one variable a shirt size never captures is fit through the leg and pouch, which is exactly where a wrong guess shows up first.
That's also why sizing complaints cluster around specific styles — jockstraps and thongs are the least forgiving, because there's simply less fabric to compensate for a guess.
How to Actually Measure Yourself
You need one thing: a measuring tape (a soft fabric one, not a metal one). Two minutes, done properly, beats guessing every time.
- Stand naturally — don't suck in, don't puff out. This is the one moment honesty pays off.
- Wrap the tape around your natural waistline — that's roughly at your navel, not where your regular trousers sit (those often sit lower, on the hip).
- Keep the tape snug against skin, not pulled tight and not loose enough to sag. It should sit the way a waistband actually would.
- Note the number in inches. That's your true waist measurement — the one every size chart on the site is actually built around, not your jeans size.
- Cross-check it against the size chart on the product page before you buy — every product page has one, and it takes ten seconds to confirm you're not about to guess.
If your number sits exactly between two sizes, go up — especially for jockstraps, thongs, and anything in mesh, where the fabric has less structural forgiveness than a classic cotton brief.
Fit Notes by Style
Briefs & Trunks
The most forgiving category — cotton and micro modal both have natural give. True to your measured waist size is almost always correct here.
Shop Briefs →Jockstraps
Fit is about the waistband, not the pouch — the strap system is meant to sit snug and stay put during movement. Too loose defeats the entire purpose of the style. When in doubt between two sizes, this is the one category where sizing down is rarely the safer call.
Shop Jockstraps →Thongs & Bold Cuts
Minimal fabric means minimal margin for error. A half-size guess is far more noticeable here than in a full-coverage brief — measure precisely, don't estimate.
Shop Thongs →Mesh
Mesh fabric stretches differently than cotton or modal — it moves with you but doesn't "give" the same way. Stick closely to your measured size rather than sizing up for comfort; sizing up in mesh usually means looser than intended, not comfier.
Shop Mesh →A ninety-second measurement now costs you nothing. A wrong guess costs you the exchange window.
Quick Reference
| Situation | What to do |
|---|---|
| Between two sizes | Size up — especially in jockstraps, thongs, mesh |
| First time in a jockstrap | Measure waist fresh, don't reuse your brief size |
| Buying mesh | Stick to your true measured size, don't size up for "comfort" |
| Gifting for someone else | Ask for their waist measurement, not their shirt size |
| Still unsure after measuring | Check the size chart on the exact product page — it varies slightly by style |
If You Still Get It Wrong
Sometimes a guess doesn't land, even with a proper measurement — bodies and fabrics don't always agree on paper. That's exactly why the exchange window exists: if the fit's off, it's a fixable problem, not a stuck-with-it one. Reach out within the window and it's sorted.
Measure once. Wear it right the first time.
Every size chart on Erobold is built around the same waist measurement — take sixty seconds now, and skip the guesswork on every order after this one.
Shop With Confidence
