Our size guide will help you find the perfect fit. If you have any questions, please use the chat icon below.
Our underwear and top sfits true to size and are fitted, however if you like your underwear/tops a little more relaxed, please size up.BOXER BRIEFS / BOXERS / TRUNKS / BRIEFS / JOCKS

Our underwear fits true to size and are fitted, however if you like your underwear a little more relaxed, please size up.
| WAIST SIZE | ||||||
S |
M |
L |
XL |
2XL |
3XL |
|
|
IN |
28-30 |
31-34 |
34-37 |
37-40 |
40-43 |
43-45 |
|
CM |
71-76 |
79-86 |
86-94 |
94-102 |
102-109 |
109-114 |
T-SHIRTS / TANK TOPS / VESTS

| CHEST SIZE | ||||||
S |
M |
L |
XL |
2XL |
3XL |
|
|
IN |
34-38 |
38-41 |
41-44 |
44-48 |
48-52 |
52-56 |
|
CM |
86-97 |
97-104 |
104-112 |
112-122 |
122-132 |
132-142 |
SHORTS / JOGGERS & PANTS
| WAIST SIZE | |||||
S |
M |
L |
XL |
XXL |
|
|
IN |
28-29 |
30-31 |
32-33 |
34-36 |
37-38 |
|
CM |
74-78 |
79-84 |
85-88 |
89-93 |
94-100 |
BRIEFS / SHORTS
| WAIST SIZE | |||||
S |
M |
L |
XL |
XXL |
|
|
IN |
28-29 |
30-31 |
32-33 |
34-36 |
37-38 |
|
CM |
74-78 |
79-84 |
85-88 |
89-93 |
94-100 |
Description
Description
One finger can save your life. An early check-up may keep you out of risk. We care about our grandfathers, Dads, Uncles, you. It is estimated that 375,304 men will die globally in 2023 of prostate cancer. Rounderbum’s One Finger collection made with luxurious modal fabric, so soft on your tush. We will donate proceeds to prostate cancer research, we have your butt covered.
Our original design gives more gluteal volume and definition, adapting perfectly to every body shape. Its design is practical, discreet and comfortable. It can be used as an everyday underwear, for extreme sports or great for sitting down for long periods of time.
Feel great in your own skin!
Superior comfort and design in men's shapewear.
FEATURES
- [PADDED Tech]®
- More bum instantly
- Short inseam boxer
- Round Bum Effect
- Removable padding
Fabric
Fabric
Care Instructions
Care Instructions
*Exclusive patented design: USD872,970S
- Reviews
- Questions
Nice Butt
The new undies do have nice padding and in loose fitting pants will help fill in the extra material. I guess my butt is already fairly round so not a huge change. Still a nice product.
Trunks
Love the trunks, got a L , but I should have ordered M.. Next order will be M
Size Difficult
I like the effect, it does add where it should. Unfortunately I seem to have ordered to big, taking into account the one RB I have, that I found too small and the advice on the site to rather take a bit bigger. So I don't know if it is my anatomy or the product. I will order one size smaller again to give it another try.
Rounderbum Canada
Dear Gordon , thank you for your comments. For a better fit please base your size on your jeans size and consult our size chart ;)
Our Techs
FAQ about shapewear
Do men use shapewear?
Do men use shapewear?
Men’s shapewear is on the rise — and for good reason.
More guys are asking, “Why should only women have these options?” From all walks of life, men are shopping shapewear to look and feel their best. Whether it’s smoothing love handles, lifting your butt with padded underwear, improving posture, or recovering post-surgery — men’s shapewear does it all. And let’s be honest — who doesn’t want a more toned, confident look?
Is it good to use shapewear?
Is it good to use shapewear?
There’s nothing wrong with wanting to feel your best — and men’s shapewear can help.
It’s great for improving posture, supporting post-surgery recovery, and boosting confidence for special events like weddings. Whether you’re looking for a more lifted look or just want extra comfort during long days, our men’s padded underwear delivers both support and style.
What does shapewear do?
What does shapewear do?
At Rounderbum, our goal is to help men everywhere feel great with shapewear.
But it does more than just boost confidence — our padded briefs add lift and volume to your butt, helping clothes fit better and adding comfort during long flights or desk time. Our compression shirts aren’t just for shaping your torso — they support better posture and are a great option for post-surgical recovery too. Shapewear isn’t just about looks — it’s about feeling good all around.








