Find the right diaper size for your child. Learn how to read the weight chart, how open diapers and pant diapers differ in fit, and when it's time to size up.
Why the right size matters so much
A diaper that fits right makes all the difference. The right size means fewer leaks, better comfort and less risk of diaper rash. A diaper that's too small presses against the skin and can leave red marks around the tummy and thighs. A diaper that's too big slides around and leaks, especially at night. No matter how good the material is, a diaper in the wrong size simply can't do its job.
The good news? It doesn't have to be complicated. With a few simple guidelines, you'll find the right size quickly, and you'll know exactly when it's time to go up.
Bammies sizes: an overview by weight
All Bammies diapers are sized by your child's weight, which is the best starting point when choosing a size. Here's a quick overview:
- The Mini, 3 to 5 kg. For the very smallest, often the first few weeks.
- The Newborn, 4 to 7 kg. With extra leak protection at the back.
- The Baby, 6 to 9 kg. For when your baby starts getting more mobile.
- The Toddler, 8 to 14 kg. For little ones on the move who need a diaper that keeps up.
- The Kiddo, 10 to 16 kg. Ideal for the start of potty training.
- The Explorer, 14 to 20 kg. Our biggest size, for older toddlers.
You might notice the weight ranges overlap. That's entirely on purpose. Children are built differently, and one 7 kg baby may fit best in The Newborn while another is happier in The Baby. Weight is a starting point, not a hard cut-off.
Weight is a start, but not the whole picture
Your child's latest weight from their check-up is a good guide, but fit also depends on how your child is built. A baby with chubby thighs may need to size up earlier. A slimmer child might stay in one size for longer. Look at how the diaper actually sits, not just what the scales say.
A few things to check:
- The waist. There should be roughly two fingers' room between the edge of the diaper and your child's tummy. Too tight and it presses. Too loose and it slides down.
- The legs. The leak guards (the elastic cuffs around the legs) should rest softly against the skin without digging in. Make sure they're properly fluffed out and not tucked inward.
- The back. The diaper should sit high up at the back, especially at night. A diaper that sits too low leaks out the back more often.
Signs it's time to change size
Children grow fast, and sometimes the size change sneaks up on you. Here are the most common signals that it's time to go up:
- The diaper leaks repeatedly, even though it's fitted properly.
- You see red marks around the tummy, waist or thighs after a change.
- You struggle to fit two fingers in at the waist.
- The diaper looks stretched or overfull after only a short time.
- The tape tabs (on open diapers) reach further out to the sides than usual.
Leaks out the back and between the legs are often the clearest sign. If it happens regularly, try moving up to the next size before troubleshooting anything else.
Open diapers vs pant diapers: differences in size and fit
It's worth knowing that open diapers (the ones with tape tabs) and pant diapers don't fit exactly the same, even when the weight ranges overlap.
Pant diapers generally have a slightly larger waist and leg opening. That's because they're designed to be pulled up and down, like a pair of underpants. So a simple rule of thumb applies:
- Is your child between two sizes in pant diapers? Choose the smaller size.
- Is your child between two sizes in open diapers? Choose the larger size.
Pant diapers often suit active children who move a lot, and situations where you need quick changes, like potty training. Open diapers with tape tabs often give a snugger fit around the waist and can be the first choice for nights.
Pant diapers come in these sizes
- The Baby Pant Diaper, 6 to 9 kg
- The Toddler Pant Diaper, 8 to 14 kg
- The Kiddo Pant Diaper, 10 to 16 kg
Night diapers: do you need a different size?
Many parents find that nights call for a little extra. Bammies bamboo diapers keep your baby dry for up to 12 hours, but if the diaper feels very full in the morning, it can be smart to try one size up for nights. A larger diaper has more absorbent area and often sits a little higher at the back, which lowers the risk of leaks.
It's also completely normal for the outside of a bamboo diaper to feel slightly damp after a full night. That's because the material doesn't contain the same amount of plastic as conventional diapers. Your baby's skin stays dry, since the bamboo fibers wick moisture away from the skin.
Not sure? Try a sample kit
The best way to find the right size is to try it. Bammies offers a sample kit with 3 diapers in every size, so you can test the fit before committing to a full pack. You can also contact customer service with your child's weight and age, and the team will help you find the right fit. If a size doesn't work, they're happy to send samples in another size, free of charge.
A quick checklist for the right fit
- Check your child's latest weight from their check-up and use it as your starting point.
- Try the diaper on and make sure there's two fingers' room at the waist.
- Make sure the leak guards around the legs are fluffed out and resting softly against the skin.
- Pull the diaper up nice and high at the back.
- Size up if you get repeated leaks or red marks.
- Choose the smaller size in pant diapers and the larger in open diapers if your child is between two sizes.
Get it right from the start
The right size saves you time, laundry and frustration. And it gives your child a drier, comfier day. Start with a sample kit or explore open diapers and pant diapers across the full range. Questions about sizing? Customer service replies quickly and is happy to help.
