The label on your old underwear is only a clue. It isn’t a measurement. Australian men’s size charts can run from a 53 cm waist to 144 cm, so guessing by S, M, or L is asking for trouble. Start with your waist, check the brand’s chart, then judge the pouch, waistband, and legs once you wear the pair.
Start With the Right Measurement Point
To choose the right underwear size for men, measure the part of your body where the waistband will sit. That sounds obvious. It isn’t. Many men measure at the belt line, the widest part of the stomach, or over a pair of jeans.
Stand upright and find your natural waist. It is usually the narrowest point of your torso, often near or just above the belly button. If you normally wear trousers lower on your hips, note that position too. Underwear may sit higher or lower than your jeans.
Use a soft tape measure. Keep it flat against your skin, but don’t pull it tight. You should be able to slip one finger under the tape. Take the reading after a normal breath. Sucking in gives you a number that your waistband won’t enjoy.
Wear only light clothing, or measure in your underwear. A thick shirt adds space. So does a loose waistband. Measure around the natural waist with a flexible tape that feels comfortable rather than tight.
Write the number down in centimetres. Don’t round it to the nearest size yet. A waist of 88 cm is still 88 cm, even if a chart groups it with 86 cm to 91 cm.
Measure twice. If the readings differ by more than 1 cm, reset the tape and try again. Ask someone to hold the tape if it keeps slipping at the back.
By now, you should have one reliable waist number and a clear idea of where the waistband needs to sit. That is the base for every chart that follows.
Measure Your Waist and, When Needed, Your Hips
Waist size is the main answer to how to choose the right underwear size men can wear comfortably. Hips matter when the waistband sits low, the cut is close through the seat, or the brand asks for both measurements.
Improve your waist reading first. Then place the tape around the fullest part of your hips and buttocks. Keep your feet together. The tape should stay level from front to back. Don’t squeeze your legs together to make the number smaller.
Most men’s underwear charts put waist first. For example, a standard underwear chart lists waist ranges beside letter sizes, with each size covering a set span rather than one exact number. That is why the chart matters more than the label sewn into an old pair.
Use hips as a second check, not as a replacement for the waist. If your waist fits one size but your hips sit well above that size, inspect the garment cut. A stretchy boxer brief may handle the difference. A firmer brief may feel tight across the seat.
Don’t measure after a hard workout. Heat and movement can make the tape shift. Take the reading when your body is at rest and your stomach is relaxed.
- For a high waist: measure where the waistband will sit, often above the hip bones.
- For a low-rise cut: measure the lower waist position as well.
- For a pouch boxer brief: check the waist, then think about room through the front and seat.
- For larger thighs: look for enough leg stretch and coverage, not only a wider waistband.
These numbers help you spot a bad chart match. A waist at the very edge of a size range deserves care. If a chart lists 71 cm to 79 cm for S, a 79 cm waist has little room left. Try the adjacent size if the brand allows it.
Size charts may span multiple lettered sizes. That wide spread helps more men find a listed size, but it also makes a letter label less useful on its own. Your measurement should lead the choice.
If you want a second way to record the numbers, use this SLY Collective men’s underwear size guide while measuring. Keep the result in centimetres so you can compare it with local charts without doing a rushed conversion.
Match Your Measurements to the Brand’s Size Chart
Once you know your waist, match it to the exact product chart. This is the part many men skip. They see M on one pair and assume M means the same thing everywhere.
It doesn’t. Size labels are shorthand. The actual range can change with the fabric, rise, waistband, leg length, and cut. A close athletic style may feel tighter than a relaxed style carrying the same label.
Read the chart on the product page, not a general chart from the same shop. Product-specific charts can use different measurements. Check whether the numbers describe body measurements or garment measurements. Body measurements tell you what to measure. Garment measurements tell you the size of the item itself.
Compare your number with the full range. If your waist is 89 cm and the chart lists M as 84 cm to 89 cm, you sit at the upper edge. If L begins at 89 cm, the waistband construction and your fit preference become the deciding factors.
For another reference, compare your measurements with this men’s underwear size chart before deciding between adjacent sizes.
Most chart entries sit around the middle of the market.
| Your chart position | What to do | What to watch for |
|---|---|---|
| Near the middle | Choose the listed size | Check pouch and leg fit after wear |
| At the lower edge | Check whether the waistband stays up | Too much looseness can cause bunching |
| At the upper edge | Compare the next size up | Digging, roll-down, or tight leg openings |
| Between two sizes | Use the larger size for more room | A loose pouch can reduce support |
That last point needs judgment. A larger size may feel better around the waist but leave the pouch loose. A smaller size may support the front but press into your skin. The right answer depends on the garment’s stretch and construction, not the letter alone.
SLY Collective Underwear gives shoppers another fit detail to inspect: the Bamboo Pouch Underwear uses a supportive hammock pouch with an anti-chafe design. That description tells you more than a plain M label. It explains where the fabric is meant to sit and what problem the cut tries to address.
Use the chart first. Use the product description second. Then check the exchange rules before ordering, since underwear returns can have hygiene limits.
Choose the Fit That Matches Your Body and Routine
The right underwear size men need for an office day may not feel right on a long flight, a hot work shift, or a gym session. Size gets the garment in the right zone. Cut decides how it behaves once you move.
Start with the waistband. It should sit flat without folding over. It should hold the underwear in place without leaving deep marks. When you bend at the waist, the band should move with you rather than roll down.
Next, check the pouch. You want space for the scrotum without loose fabric flapping at the front. You also want support without pressure. A hammock-style pouch, such as the one used by SLY Collective Underwear, can separate the front from the legs and reduce the cramped feeling some men get from a flat front.
Then check the legs. Longer legs can help if your thighs rub or the fabric rides up. A shorter cut may work better under slim trousers. If the leg hem sits at the widest part of your thigh, it may creep upward as you walk.
Match the style to the day:
- For desk work: focus on a flat waistband and a pouch that doesn’t press when seated.
- For walking or travel: look for legs that stay down and fabric that handles warmth.
- For active work: choose enough thigh coverage to limit skin-on-skin rubbing.
- For slim trousers: avoid extra fabric that bunches under the seat or fly.
SLY Collective’s longer-leg design targets riding up, while the pouch gives the front more room. That can suit men who have spent years pulling their underwear back into place. Still, no cut works for every body. If the waistband fits but the leg opening pinches, change the style or size rather than forcing the pair to work.
Fit should feel secure when you stand, sit, squat, and walk. Test all four. The mirror only shows one position.
Check the Fit After Wearing and Washing
The first fitting tells you whether the size is close. A full day tells you whether it is right. Put the underwear through normal movement before judging it.
Look for clear signs:
- The waistband stays level without rolling.
- The pouch stays in place without pinching.
- The leg openings don’t cut into your thighs.
- The fabric doesn’t bunch at the crotch or behind the knees.
- You don’t need to pull the garment up every few minutes.
Walk up stairs. Sit at a desk. Bend down. If the pair works in those positions, it has passed a fair first test. If you feel pressure, heat, or rubbing within an hour, don’t blame your body. The size or cut may be wrong.
Wash the pair according to its care label before making a final call. Fabric can change after washing, especially when exposed to high heat. Bamboo fabric needs care if you want to keep its original feel and shape. Cold washing and low heat or air drying are safer choices than a hot dryer.
After washing, check the waistband and leg openings again. Did the band lose its hold? Did the pouch twist? Did the legs shrink enough to ride up? These are fit problems, not small details, because they show up during the next long day.
Keep notes if you’re testing a new brand. Record your waist, chosen size, style, and what happened after washing. That gives you a useful reference for the next order.
If the waist feels right but the front still feels wrong, revisit the pouch design before changing sizes. A different cut may solve the issue more cleanly than going up or down.
Frequently Asked Questions
How do I know what underwear size I am?
Your waist measurement is the starting point. Measure around the natural waist with a soft tape, then match the number to the exact brand chart. If you sit between sizes, inspect the cut and choose the larger size when you need more room. Don’t rely on the letter from an old pair.
Should men’s underwear be tight or loose?
Men’s underwear should feel close but not restrictive. The waistband must stay flat, while the pouch should give support without pressing into the scrotum. The legs should hold their place without cutting into your thighs. If you keep adjusting the garment, the size or style probably needs to change.
Do I measure my waist or hips for men’s underwear?
Measure your waist first because most men’s underwear charts use it as the main size point. Measure your hips as a second check when the style sits low or the chart asks for both. If the two measurements point to different sizes, review the garment cut and its stretch before ordering.
What should I do if my waist measurement is between sizes?
If your waist falls between sizes, compare both ranges and try the larger size when comfort is your priority. The larger option can prevent digging and roll-down. But check the pouch and leg openings too. A waistband that feels better won’t fix a loose front or legs that ride up.
Does pouch design affect underwear sizing?
Pouch design affects how the same size feels, even when the waist measurement matches. A shaped pouch can give the scrotum more room and support than a flat front. When choosing underwear, read the fit description beside the chart. SLY Collective Underwear uses a hammock pouch, so the front fit is part of the size decision.
Conclusion
Measure your natural waist in centimetres, match it to the product chart, then test the waistband, pouch, and legs through a full day. For a supportive cut with a hammock pouch and longer legs, see SLY Collective Underwear and use your measurement before choosing a size.