Every parent wants diapers that don't leak. And yet so many of us have stood there at 3 a.m. with soaked sheets, a crying little one and the feeling that the diaper let us down. Here's the good news: leaks are rarely down to a bad diaper. Almost every time, it's because the size or the fit doesn't match your child right now. And that's fixable. In this guide we'll walk through how size and absorption are connected, how to read where the leak is happening, and what to know about night diapers in bigger sizes as your child grows.
Leaks are rarely the diaper's fault. Usually, it's the size
A diaper can only do its job if the liquid ends up where the absorbent core is. If the diaper sits too low, too loose or too small, the liquid runs past the core before it can be soaked up. And then it doesn't matter how good the material is.
Our diapers have bamboo fibers against the skin, and bamboo can absorb up to three times more liquid than regular cotton. That gives you a diaper that stays dry for up to 12 hours when the size is right. But absorption is a capacity, not a promise that holds no matter the fit. The right size plus strong absorption. That's the whole equation.
Read where it's leaking
Where on the diaper the leak happens tells you pretty precisely what needs to change. Here's how to read the signals.
It leaks at the back
A classic sign that the diaper sits too low or the size is too small. Pull the diaper up a little extra high at the back so it sits high on the waist. Still leaking at the back? Then it's usually time to go up a size.
It leaks between the legs
Check the leak guards first. The elastic around the legs should be fluffed out properly and facing outward, not folded in. If it's sitting right and it's still leaking between the legs, that's a common sign your child needs the next size up.
It leaks at the front
Common with boys and with children who sleep on their tummy. Make sure the diaper is pulled up properly at the front and that there's about two fingers' worth of room at the waist. That way it sits snug without gaping.
The whole diaper is soaked in the morning
Here the fit isn't the problem. The diaper is simply full. Your child pees more than the size can handle over a full night, and only more absorption will help. Go up a size for nights. A bigger size means a bigger core and more capacity, even if your child still fits the smaller one during the day.
Size and absorption: why they go together
Many people think size is only about how the diaper fits. But size also decides how much liquid the diaper can hold. The bigger the diaper, the more absorbent material. That's why we so often recommend going up a size when it leaks at night, fills up fast, or leaks at the back and between the legs.
Two things to keep in mind:
- Our diapers run slightly larger than many other brands. If your child is between two sizes, we recommend the larger one in open diapers and the smaller one in pant diapers.
- The weight range is always a guide. Fit can vary from child to child depending on how they're built around the tummy, legs and back. The body decides, not the number on the box.
Night diapers in bigger sizes: when your child outgrows the night diaper
Here's a question we get a lot: what do you do when your child is big, sleeps for long stretches and pees a lot at night? Many brands stop early in their size range, which makes it hard to find night diapers in bigger sizes that actually hold. We go all the way up to 20 kg, precisely so nights stay dry for the biggest explorers too.
- The Toddler, 8 to 14 kg. For active kids who climb, run and sleep deeply. Often the first step up when night leaks start.
- The Kiddo, 10 to 16 kg. More capacity for children who sleep long and pee a lot at night.
- The Explorer, 14 to 20 kg. Our biggest size for older toddlers who still need a diaper that lasts all night.
A common trick is to use one size during the day and the size above at night. The day diaper stays trim for playtime. The night diaper gets more core and more time.
Open diaper or pant diaper at night?
Pant diapers are fantastic during the day. They move with the play, they're easy to pull onto a child who won't lie still, and they work well once potty training begins. At night, things look a little different. Pant diapers generally have a larger waist and leg opening than open diapers in the same weight class, and that extra freedom of movement can leave a little more room for leaks over a long night.
If your child leaks in a pant diaper at night, our tip is to try an open diaper in the size above, just for nights. With the tape tabs you can adjust the fit precisely around the waist and pull it high at the back. Keep the pant diapers for daytime. Plenty of families do exactly that.
Want pant diapers on subscription for the daytime? You'll find them in our monthly box of pant diapers. Need open diapers for nights? They're in the monthly box of open diapers. You can change size any time in your account, with no lock-in period.
Good to know about bamboo at night
Let's be honest about one thing. Bamboo diapers have significantly less plastic than regular diapers, and that means the outside can sometimes feel slightly damp in the morning after a really long night. That doesn't mean it leaked. The bamboo fibers wick liquid away from your child's skin, which stays dry, while the outside doesn't have the plastic layer that conventional diapers do. If the outside feels damp, though, that's a signal the diaper is working close to its limit, and it's smart to go up a size for nights.
Parents who've found the right size often put it like this: "No pee leaks at night, and stays sealed during the day." Or simply: "Not once have they leaked." That's where we want you to get to.
Quick checklist before you change size
- Fluff out the elastic around the legs so it faces outward.
- Pull the diaper up high at the back.
- Check for two fingers' worth of room at the waist.
- Leaking at the back, between the legs, or the whole diaper soaked in the morning: go up a size.
- Pant diaper leaking at night: try an open diaper in the size above for nights.
- Still leaking: get in touch with your child's weight, age and which size you've tried. We'll send samples in a different size free of charge, and in the case of leaks or quality issues you'll get a replacement box.
Your next step
Grab your child's latest weight from their checkup. If they're in the upper half of their weight range, or leaking at night, pick the size above for nights and add it to your monthly box. Start with The Toddler, move on to The Kiddo and land in The Explorer as your child grows. The diapers are delivered to your door every month, you change size whenever you want and can pause whenever it suits. Less leak. More sleep. For both of you.
