Our Guide to 

choosing the right size

We want to make sure you choose the correct size. So let us help you to pick the right size and get the perfect fit.

How It Works

If you have any questions about what size you should order, pick the tab below with the item type you need help with. We have recommendations and size charts for you so you can pick the right size.

  • Boxer Briefs
  • RELAX Shorts
  • T-shirts
  • Undershirts
  • SWM Trunks

4RM Boxers Briefs

With our varying collection of 4RM Underwear know that our underwear are made to provide maximum support while maximizing comfort. What this means is that if you choose the measurement that reflects your waist, these are designed to fit you comfortably but not tight. They will be snug and able to stay in position due to our special 2in waistband. If by chance you like your underwear looser, by all means go a size up. If your measurement falls in between two ranges in size, we recommend choosing the size above your measurement. If you want it tighter, you can go a size down. But due to fit, we do not recommend going a size down.

Be sure to measure yourself around the area in which you will be wearing your underwear. Meaning if you like to wear them around your natural waist measure there, if you are like us we wear them a little lower(but high enough to cover up), then measure there. If you oddly like them over your stomach, hey do you. Whatever your preference we got you covered. 

Don't try to overcompensate by picking a size larger than what you measure. We developed these to fit you just right given your waist measurement. Remember that these offer plenty of stretch but provide ample support.

We are here to combat plumbers crack.

RELAX Shorts

Our shorts in our RLX collection are designed to maximize your leisure. Allowing you to chill but do so in style and comfort.

Be sure when choosing your size, you measure where you plan on wearing the shorts. Whether high or low make sure you measure the waistline you plan on wearing them at. If your measurement falls in between two size ranges, choose the larger size if you want them to fit a little more loose, or a size down if you want them to be a little more snug. The waist to these will provide plenty of room to adjust with a fully wrapping drawstring as well as flexible waist. Allowing you to wear them as loose or tight as you choose.

Designed to be free flowing and extra comfortable. This means they will be looser fitting around the legs than underwear of course but still have ample waist support to keep you covered comfortably.


Our mandatory t-shirts are made to be a great top layer to any wardrobe. We want to provide a shirt that allows you to move comfortably, but to also hold firm and keep you comfortable.

When choosing your size make sure to measure your chest and let us do the rest. These are made to be stable in construction but a little looser in fit than an undershirt. If your size falls in between two size ranges, pick the larger size for a looser fit or the smaller size if you desire a tighter fit. We recommend going up a size when in doubt, because these are not made to provide much stretch like our undershirts.

Don't overcompensate on the size unless you like your clothing baggy. Which we do not recommend. We give you plenty of room when you pick your correct size.

4RM Undershirts

Our 4RM Undershirts are made to provide you the most comfort and support possible. We use the best materials to keep you adequately supported but to also allow maximum comfort.

When choosing your size, make sure that you choose the size that best reflects your chest measurements. Our 4RM undershirts are designed to provide adequate stretch but also providing an added level of support. Keeping you in place throughout your day. If your size fits between two ranges, pick the larger size if you want a looser fit, or a size down if you want a tighter fit. We recommend going down a size if you must pick because our shirts provide extra stretch and undershirts shouldn't be baggy. Unless thats your preference. 

Know that when we designed these, we did so to make sure you are supported throughout the day. Choosing the right size will make sure you're adequately supported and it makes each additional layer on top that much more appealing.

SWM Trunks

With our SWM trunks we want to make sure you are covered comfortably. Our trunks are made to give you maximum comfort while wearing so we provide plenty of room to maneuver allowing you to be as active as you want to be.

Be sure to pick the size that reflects the waistline of which you plan on wearing them. If you like to pull them up a little higher, measure that area around and choose the corresponding size. If your size falls in between two size ranges, pick the larger size if you want a more looser fit, go a size down if you want it to fit a little more snug.

These are also made with a net to keep you protected and adequately situated whether you wear underwear underneath or not.

Whatever you do, don't try to overly overcompensate, we make the items with your waist measurement in mind. These are made to be relatively loose fitting around the legs and others areas but still supportive at the waist.