Size guide
Find your perfect fit
Our underwear is designed to sit close to the body. Measure your waist, check the chart and pick your size. It takes less than a minute.
Men's underwear size chart
Most Arjen Kroos underwear and swim briefs follow this chart. Some styles are cut slightly differently. If a product page shows its own size chart, that one takes priority.
| Size | Waist (cm) | Waist (inches) |
|---|---|---|
| S | 66–74 | 26.0–29.1 |
| M | 71–79 | 28.0–31.1 |
| L | 76–84 | 29.9–33.1 |
| XL | 81–89 | 31.9–35.0 |
| XXL | 86–94 | 33.9–37.0 |
| XXXL | 92–100 | 36.2–39.4 |
The ranges overlap because our fabrics stretch. If you fall between two sizes, see the fit tips below.
How to measure
Measure your waist in 4 steps
01
Use a soft tape
Measure over bare skin or thin underwear, never over jeans or a belt.
02
Find your waistline
Measure around the point where you normally wear your underwear, usually 2–3 cm below your navel.
03
Keep it level
The tape should lie flat and parallel to the floor: snug, but not tight.
04
Match the chart
Find your measurement in the waist column and choose that size.
Fit by style
How each style should fit
Jockstraps
The waistband and straps should sit flat without digging in. Between sizes? Size up for comfort, size down for maximum lift.
Shop jockstraps →Thongs & G-strings
Made for a minimal, close fit. If you prefer less pressure on the pouch, choose the larger size.
Shop thongs →Boxer briefs & trunks
The legs should stay in place without riding up. Size down for a sleek, second-skin look.
Shop boxer briefs →Swimwear
Swim fabrics tighten slightly when wet. Take your usual size, or size up if you are between two.
Shop swimwear →Shapewear & compression
Designed to be snug. Stick to your measured size: sizing down won't add support, only discomfort.
Shop shapewear →Undershirts & compression tops
Garment measurements, taken flat and relaxed. The fabric stretches to fit your body.
| Size | Chest (in) | Chest (cm) | Length (in) | Length (cm) |
|---|---|---|---|---|
| S | 22.0–26.0 | 56–66 | 21.3 | 54 |
| M | 23.6–27.6 | 60–70 | 22.0 | 56 |
| L | 24.4–28.3 | 62–72 | 22.8 | 58 |
| XL | 26.0–30.0 | 66–76 | 24.0 | 61 |
| XXL | 26.8–31.5 | 68–80 | 24.4 | 62 |
Size by height and weight
| Height / Weight | 99 lb · 45 kg | 110 · 50 | 121 · 55 | 132 · 60 | 143 · 65 | 154 · 70 | 165 · 75 | 176 · 80 | 187 · 85 | 198 · 90 | 209 · 95 | 220 · 100 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 5'5–5'7 · 165–170 cm | S | S | M | M | L | L | XL | XXL | XXL | XXL | – | – |
| 5'7–5'9 · 170–175 cm | S | S | M | M | L | L | XL | XL | XXL | XXL | – | – |
| 5'9–5'11 · 175–180 cm | – | S | S | M | L | L | XL | XL | XXL | XXL | – | – |
| 5'11–6'1 · 180–185 cm | – | – | S | M | M | L | XL | XL | XL | XXL | XXL | – |
| 6'1–6'3 · 185–190 cm | – | – | – | M | M | L | L | XL | XL | XXL | XXL | XXL |
| 6'3–6'7 · 190–200 cm | – | – | – | – | M | L | L | L | XL | XXL | XXL | XXL |
T-shirts & casual tops
Garment measurements. Compare with a T-shirt that fits you well, laid flat.
| Size | Chest | Body length | Sleeve length |
|---|---|---|---|
| XS | 37 in · 94 cm | 26.5 in · 67 cm | 8.5 in · 22 cm |
| S | 39 in · 99 cm | 27.5 in · 70 cm | 9 in · 23 cm |
| M | 41 in · 104 cm | 28.5 in · 72 cm | 9.5 in · 24 cm |
| L | 43 in · 109 cm | 29.5 in · 75 cm | 10 in · 26 cm |
| XL | 45 in · 114 cm | 30.5 in · 77 cm | 10.5 in · 27 cm |
| XXL | 47 in · 119 cm | 31.5 in · 80 cm | 11 in · 28 cm |
Sizing questions
What if I'm between two sizes?
For stretchy fabrics like mesh and ice silk, choose the smaller size for a snug fit or the larger size for more room. For cotton and swimwear, we recommend the larger size.
Do sizes differ between styles?
Most of our underwear follows the chart above, but some styles are cut smaller or larger. If a product page has its own size chart, use that one.
Can I exchange the wrong size?
Yes. Unworn items in their original sealed packaging can be exchanged within 14 days. See our returns & exchanges.
Still unsure about your size?
Send us your waist measurement and the product you like, and we'll recommend the right size.