Diaper Fit

by Julie Siewert July 22, 2018

Diaper Fit

I spend far too much time online in Facebook Mom groups. There, I said it. And if you also have also ventured into some of these groups, you’ve learned a few things. For as much as we are all different, there are some similarities. I see some of the same questions coming up time and time again in these groups. Since I’m “the diaper lady” those are the questions I pay attention to. Moms are always asking:

“why are these (insert brand name here) diapers leaking?”

“what brand of diapers do you use overnight, my (insert brand name here) diapers are always leaking!”

“these (insert brand name here) diapers aren’t working for my baby, what do you use?”

“why is my baby pooping so much that it’s coming out the back?”

You want the answer? I’ll tell you.

It’s all about the fit. That’s it. There is no magic brand of diapers that will work perfectly for all your closest Facebook friends AND for you, too. Every baby is different, and so every diaper fits a little different also.


Photo of baby in diaper with text "the basics of Diaper Fit Solve the leaking, messes and confusion by understanding WHY they happen"


 A diaper (disposable or cloth) is basically an absorbent material secured around your baby. The absorbent material does its job of soaking up what your baby gives it. There is elastic (or something similar) around the legs and back to keep all the mess inside.

You see where I’m going with this. The problem isn’t with the absorbency (usually) it’s with the FIT! If it’s not secured properly, the diaper will not contain all your baby’s “output”.

We all know that babies come in all sizes and shapes. Think “chunky monkey” vs. “chicken legs”. The same diaper won’t fit both of them well.

What you may not know is that all diapers fit a little different, too. Take this example:

Diaper Fit Comparison

Take 3 diaper brands: Target’s Up & Up, Seventh Generation and Earth’s Best. All three brands pictured are size 1 diapers (fits 8-14 lbs.). The first photo shows how much wider the Target diaper is than the Seventh Generation. If you’ve got a baby with a wide “stance” the Seventh Generation diapers may not provide enough coverage. On the flip side, the Target diapers may be too wide or bulky on a smaller baby. The second photo shows how much taller the Seventh Generation diapers are vs. the Earth’s Best diaper. So, a tall baby may not get enough coverage from the Earth’s Best diaper, while a shorter baby may be drowning in a Seventh Generation diaper.

See how I keep saying “may”? You never really know how a diaper will fit your baby until they’re wearing it. You might need to try multiple brands of diapers to find the right one for your baby.


 Photo of 8 packs of Diaper Samples with 5 star review text "The perfect service! I purchased this sampler for myself because I was dealing with the wrong fit for the one brand of diapers that I purchased for my little one. The combination of diapers allowed me to find my favorite one and a few backup brands that I could purchase as alternates. Who knew diapers could fit in completely different ways?! The shipping was fast and I'm definitely purchasing this as baby shower gifts for everyone I know. Thank you Diaper Dabbler for giving parents an easier way to find the right diaper for their little ones! A++"

Diaper sizing and weight ranges

Most diaper brands follow “traditional” US sizing (for example; size 1 is 8-14 lbs.). Many eco-friendly diaper brands are made outside the US, which is why the weight ranges on their diapers are often slightly different. Make sure you check, size 1 is not the same everywhere.

You can check out our Diaper Brand Information page to find more information about each brand including links to their in-depth “Spotlight Series” post which includes their weight chart.

Even with weight ranges printed on the diaper packaging, there is overlap. Newborn diapers can fit babies up to 10 pounds, while size 1 diapers fit babies 8-14 pounds. It’s all about how a diaper fits YOUR unique baby.

Fun fact, CVS Health brand diapers have a “smart fit” indicator on their diapers to help parents judge when it’s time to move up to the next size. That only includes the waist size, but it’s still helpful.  You can read more about CVS brand diapers here.

Many experienced Moms will tell you that if your baby’s diaper suddenly starts leaking when it didn’t used to before, it may be time to move up a size. Bigger size diaper = more absorbent square footage = better absorbency PROVIDED that it still fits well (if the leg holes are too big, baby will pee right out the side).


 Baby diaper fit



It bears repeating.  Bigger size diaper = more absorbent square footage = better absorbency PROVIDED that it still fits well.

As babies grow and start eating and drinking more, their ”output” increases. More poop and pee mean that diapers need to absorb more. Thankfully they are growing into bigger diapers, so there is more space in the diapers for absorbent material.

Do the different brands of diapers absorb differently? Is one “better” than the others?

Yes and no. Yes, they do absorb differently. And some use different absorbent materials. Huggies adds FSC Certified wood pulp to their absorbent materials. Eco by Naty uses less SAP (Super Absorbent Polymer) in their diapers. Earth’s Best includes corn and wheat starch for absorbency. Every brand is different. Are any more absorbent than others? Maybe. Is it a significant amount? Probably not.

You can read more about what is or isn’t in each diaper brand on our Diaper Brand Research and Information page.

If you have a growing baby that sleeps for longer stretches at night, you may need more absorbency than many diapers can provide you. Some brands make an “overnight” diaper with extra added absorbency. They typically start around size 3.


 Multiple brands of diapers on a shelf with teddy bear


Tips and tricks

To find a diaper that will fit your baby properly, you really will need to try a few different brands. It’s easiest and best to try them all side by side with a Diaper Sampler package. You can try a few diapers in each brand to get an idea of the fit and function of each one. There are packages that make excellent baby gifts for an expectant couple or custom packages for parents who know which brands they’d like to try.

If your baby’s diaper is “suddenly” leaking, it might be time to size up.

If your baby’s diaper often squirts poo up their backs, it might be time for the next size up diaper.

If your baby is sleeping long stretches at night and their diaper is consistently leaking only at night, you might want to consider overnight diapers with more absorbency.

Diapers cost more (per diaper) the bigger the sizes get. You could consider keeping them in a smaller size and just switching brands of diapers (one that still fits but fits bigger) to keep your cost down.

If you have a toddler and even overnight diapers aren’t holding overnight, you’re probably almost ready to potty train. Toddlers will unconsciously begin holding their bladder as they get closer to being ready to potty train. You may find that they are doing this at night (“holding it” until they can’t any longer and peeing a whole lot instead of peeing a little bit each time all night long). This makes it almost impossible for any diaper to hold it all (since it’s coming all at once). Take heart, you’ll be done with this soon.

If you have a really big toddler/big kid and you’re having a hard time keeping the urine in all night, there are “big kid” sized disposable overnight underwear (one brand name is GoodNites). They offer more absorbency with bigger sizing. The fit of these may be tough on smaller kids, though.


Diaper Dabbler Diaper Variety Packages 


There you have it. If you have read this far, you deserve a prize for knowing all there is to know about diaper fit. Can we make a “diaper fit award”? This sounds like a good idea.

Do you have any Mom advice as far as diaper fit? I’d love to hear it in the comments!


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