Sized vs One Size Cloth Diapers: Why You May Want to Consider Both!


When I first started cloth diapering seven years ago sized diapers were more popular and available than today because one-size diapers were somewhat new, but the one-size diapers were all the rage.

Following the trend, I chose all one-size diapers systems, and really, I think that was a wise decision for me, with my one child who potty trained late-ish and didn’t go to daycare, but that may not be the case for everyone.

If you’re considering a sized diaper system, keep reading because your gut may be leading you in the right direction and I’m going to tell you all the pros and cons of sized and one-sized diapers; but first, let’s make sure we are using the same cloth diaper lingo.

What are One-Size Cloth Diapers?

Illustration of a One-Size Cloth Diaper on babies of different ages.

One-size diapers are just that, a one-size-fits-all diaper that aims to be so adjustable that it can fit any baby from the newborn stage to potty training. These diapers can have snap or Velcro “wings” that make the waist smaller or larger, and will also have snaps along the center of the diaper to make the “rise” shorter or longer to accommodate different heights.

Will One-Size Cloth Diapers Fit Newborns?

Now does a one-size system really fit a baby from birth to potty training? Not usually. It depends on how big or small your newborn is. Most one-size diapers claim to fit babies from about 6 or 7 lbs to 35 lbs. Often these diapers fit best from about 8lbs on.

According to Medical News Today, “The average weight of a baby born at 37–40 weeks ranges from 5 lb 8 oz to 8 lb 13 oz.”

Since most one-size diapers fit best from about 8lbs on, you can expect a good many babies won’t fit them at birth.

If you have a 9 lb baby, you’ll be fine, but that’s more of an exception than the rule.

When Do One-Size Cloth Diapers Fit?

In my experience, one-size diapers fit most babies well around two or three months old. Of course, in the case of twins, multiples, or premies, it can be even longer before they reach that 8lb mark.

Once they do fit, can a one-size last your child up until potty training? Yes. Most one-size diapers fit up to about 35lbs. While your 9-month-old, delightfully-rolly baby may be 25lbs or more, you don’t have to panic; most kids won’t reach that 35lb mark until they are much older. This is because as babies grow their weight gain slows and they stretch out, growing taller.

With the exception of any developmental delays that delay potty training, most babies will potty train before they reach the weight limit of those one-size diapers.

What are Sized Diaper Systems?

Sized diapers are diapers that come in several sizes, of which you’ll need a few to diaper your baby from birth to potty learning, just like disposable diapers. The sizes may be small, medium, large, or size 1, size 2, etc.

The most common sized diaper systems you’ll find are prefold cloth diapers and fitted cloth diapers. Both of these cloth diaper types need to be used with a cloth diaper cover, and many times parents will choose a cloth diaper cover that’s one-size — although Thirsties Duo Wraps and diaper covers are great cloth diaper cover options that are sized.

Sized diapers with the pul built-in — like all-in-ones, all-in-twos, and pocket diapers — will still have snaps or Velcro at the top to make the diaper fit well around the waist, like disposables. These diapers often won’t have any adjustability in the rise, however. This isn’t a hard-and-fast rule however as Thirsties Duo Wraps, which are sized diaper covers, do have rise snaps.

If you compare different sizes in a sized diaper system, you’ll see each size is bigger, just like your baby’s clothing.

Thirsties sized duo wraps.

Pros and Cons of One-Size Cloth Diapers

One-Size Cloth Diaper Pros

  • Less Expensive (if Only Using on One Baby). With one-sized diapers, you just need a single set to get you through the diapering years. While constant use is harder on the diapers, if you’re like me and are only planning on one child, you don’t need to worry about making your diapers last longer, one-size diapers age going to come out less expensive in both the short and long run.
  • Good for Multiples. One-size diapers are a great way to cloth diaper a toddler and baby at the same time. You will need to purchase more diapers for your rotation though. Click here to find out how many diapers is needed for each age.
  • Flexible. Often, babies will grow into a size of diaper (or into a larger rise setting) and then, when they crawl or walk, go back down a rise snap. One-size diapers give you many ways to customize your baby’s diaper fit according to his or her stage.
  • Convenient. One set of diapers, that’s it. There isn’t a need to buy more when you need a new size.

One-Size Cloth Diaper Cons

  • Fit Difficulties. It seems counterintuitive, but for smaller babies, one-size diapers can difficult to get the right fit for your baby. No cloth diaper is going to be 100% perfect and babies go through growth spurts that can be odd. For example, my daughter had chubby thighs but a really skinny waist. A few of her (ah-hem, cheap) one-size diapers just didn’t have a good in-between setting for her.
  • Bulk. Especially for smaller babies, all of that extra material made to create adjustability also creates bulk that you just don’t get with sized diapers.
  • Wear and Tear. When my husband and I set out to buy our first set of diapers for our son our plan was to use them this next time with our daughter. Well, after almost three years of use, washes, drying, stripping, and the list goes on, we had to purchase a new set for our daughter. Think about it, if you were to sleep in the same sheets day after day washing them every other week or so, I highly doubt they’d last three years much less six.
  • Boring! With only one set from birth through potty training, many people overbuy diapers just to collect all the cute prints.

Pros and Cons of Sized Cloth diapers

Sized Cloth Diaper Pros

  • Easier to Find a Good Fit. We don’t put our babies in one-size-fits-all disposable diapers, because each diaper size is meant to fit a baby during a specific point in their development. For example, a smaller-sized diaper can accommodate the chubbiness before the movement phase.
  • Trimmer Fit. With less material in the front of the diaper to adjust the rise, sized diapers are just naturally trimmer than one-size diapers.
  • You Get to Purchase More Cloth Diapers! Yay for more fun diapers to buy! Honestly, I don’t know what it is about cloth diapers that make them so addictive, but it’s the ultimate guilt-free parent collectible.
  • Cloth Diaper Stash Will Last Longer. Again, less wear and tear equals longer-lasting diapers. Chances are better that you’ll be able to use your set of sized diapers with more than one child than your set of one-sized diapers.  
  • Less Confusion at The Changing Table. For people who don’t have experience with cloth diapers, like — often the case for daycare staff, grandparents, etc. — all the snaps on one-size diapers can be intimidating. Sized diapers have fewer options and are closer to disposable diapers at the changing table.

Sized Cloth Diaper Cons

  • More expensive, at first. I think you have to look at using a sized diaper system as a long-term investment. If you’re on your last child and are just starting your cloth diaper journey sized diapers may not make sense financially for you.
  • Not as convenient. You have to purchase more diapers as your baby grows. If you’re feeling overwhelmed or anxious about cloth diapering this may totally turn you off.

Conclusion: Are One-Size or Sized Diapers for You?

All in all, whether you choose to do with the standard one-size diapers, or a sized system will come down to two things:

  1. What Type of Cloth Diapers You’re Going With: Again, prefolds and most daytime fitted diapers (like Green Mountain Diapers‘ workhorse diapers) come in sized options, but very few pocket diapers for example are sized.
  2. If You’re Going to Cloth Diaper More Than One Child. Sized diapers make sense if you’re planning on using them for multiple children as they will last longer, but one-sized diapers are less expensive if you’re just using them on one child.

If you need more help choosing the right cloth diapers for you, click here.

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