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Adult Diaper Size Chart + How to Find the Right Fit

Man holding measuring tape around his waist to take measurements while other older adults are socializing in the background

Kara Miller |

Getting the right size of protective underwear or adult diaper isn’t just about comfort; it’s also about making sure the product works the way it should. Well-fitting briefs and protective underwear can make you more comfortable and confident, when going out with friends and romantic partners, and can eliminate the messes that come along with poorly fitting underwear.

As many as 80% of people with incontinence are wearing the wrong size product, so we’ve created a simple guide to help you learn how to find the proper fit and get the most out of your protective underwear.

Why the Right Adult Diaper Size Matters

Fit is one of the most important factors determining whether your incontinence underwear or adult diapers actually work.

If your underwear is too tight, liquid might be squeezed out and stain your clothing. Too-tight underwear can also cause chafing, especially around the leg openings, and will irritate your skin by holding urine and stool too close for comfort. Overly tight underwear can even affect the circulation in your legs or groin area, causing pain or discomfort.

If your underwear is too loose, it won’t be able to catch liquid before it runs out through the leg openings. Loose underwear can also leak from the waist opening if you have an accident while lying down. In addition to leakage, overly large diapers and underwear can be bulky, stick out of your clothing, or even bunch up when you walk, causing pinching and chafing.

How Incontinence Underwear and Briefs Should Fit

When your adult diapers or incontinence briefs fit well, they should be snug against your waist and around the legs, but shouldn’t be so tight that they dig into your skin and cause red marks. They should also not bunch up or pinch when you walk, or feel too restrictive.

In addition to feeling comfortable, well-fitting briefs and underwear shouldn’t leak. Leakage from your protective underwear is not normal, and is a sign that your current product isn’t a good fit for you.

Signs You Have the Wrong Size Product

When your protective underwear fits well, you should be able to wear it without noticing it. If you are bothered by any of these problems, you might need to find a different size or style:

  • Frequent leaks: This usually happens when the underwear is too big, so the leg cuffs can’t lie flat against your skin and hold in bladder leaks. However, it can also happen if the underwear is so small that it tears, or if liquid is getting pressed out of the absorptive core because it’s too tight.
  • Chafing: If your underwear is too tight, then you’ll probably feel the leg cuffs cutting into your thighs, causing redness and irritation. If it’s too loose, then the material could bunch up and cause chafing between your legs or other areas where the material gathers.
  • Pain or restricted blood flow: This is a sign that your underwear is too small. If you feel tingling or numbness around your midsection, or if you’re in pain when you wear your underwear (more common in men), then it’s too tight.
  • Extra material showing: If you have bulky material that can clearly be seen under your pants, or if extra material is showing outside your regular clothing, that’s a sign your briefs are too big. Properly fitting protective underwear should fit discreetly under your clothes and not bunch up when you walk.

Common Misconceptions About Incontinence Product Sizing

Before you shop for your incontinence products, here are a few common misconceptions to steer away from:

Bigger sizes are more absorbent: This is not true. The only thing that affects how much liquid a particular style of underwear can hold is the number of absorbent cores in the product. For example, Because Maximum Protection underwear for men and women holds four cups of liquid regardless of whether it’s a size small or a size extra-large.

Men’s and women’s styles are the same: Also a misconception. There are real differences in the cut of men’s-style and women’s-style underwear, to accommodate different anatomy, so if you buy a unisex product and find it uncomfortable, look for brands that sell styles in men’s and women’s cuts and try out a design more specific for your body shape.

How to Measure for Adult Incontinence Products

Most brands size their products based on waist or hip size. Like many other brands, Because Market underwear uses whichever measurement is bigger. So, if your waist is 30 inches, but your hips are 40 inches, then you’ll use your hip size to decide which size of briefs to buy.

Wrap the measuring tape around your waist, around the same height as your belly button, and then compare your measurements to the size chart of your preferred brand of incontinence underwear. If your hips are bigger than your waist, then use that measurement instead. Find your hip circumference by wrapping the measuring tape around the widest part of your hips, and check this number against the size chart.

Waist and hip size aren’t everything, however. If your measurements put you in between sizes (for example, you could be a medium or a large), you can check your height and weight against the size guide provided by the brand (usually available in the product description). These weight guides offer more detailed guidance on what size is likely to fit you.

Because Market Disposable Briefs Size Chart

Because Market has a quiz to help you choose which size and style of incontinence product is best for you. We offer both men’s and women’s styles of protective underwear, but the basic sizing is the same regardless of which style you choose. Using your waist (or hip) size, you can order underwear in Small/Medium, Large, Extra Large, or XXL:

Size Chart

If you’re in between sizes based on your waist measurement, you can also check the height and weight chart to find your ideal size:

Size chart

Every brand and style of protective underwear (briefs and diapers that close with tabs, reusable underwear, and disposable underwear) will have its own unique fit, so it’s worth it to try a few before you settle on a specific style or size. Many brands offer sample packs, so don’t be shy, and try out the ones you think will work best for you.

Because Market offers a starter pack when you take our bladder protection quiz. Let us know if the fit on your first pack isn’t quite right, and we’ll help you find the correct size!



American Urological Association. (n.d.). Urinary incontinence. Retrieved from