Diaper Size Calculator

Find the perfect MamyPoko diaper size for your baby in seconds. Enter your baby's weight and get instant recommendations.

kg
5 kg

Adjust the weight slider above to see your recommended size

MamyPoko Size Guide

Preemie
1.5–3 kg
NB
Up to 3 kg
S
4–8 kg
M
7–12 kg
L
9–14 kg
XL
12–17 kg
XXL
15–25 kg
XXXL
18–35 kg

How to Choose the Right Diaper Size

Choosing the correct diaper size is one of the most important decisions you'll make as a parent. A diaper that's too small can lead to uncomfortable leaks and red marks on your baby's skin, while a diaper that's too large won't fit properly and offer adequate protection.

Weight is the Primary Factor

Unlike clothing, diaper size should be based primarily on your baby's weight, not their age. Every baby grows at a different pace—some babies are naturally larger while others are smaller. This is why the weight-based sizing system used by MamyPoko works so well. You can also use age as a general reference, but always prioritize your baby's actual weight.

Signs Your Baby Needs a Size Up

Pay attention to these warning signs that indicate it's time to move to the next size: red marks or indentations around your baby's waist, thighs, or legs after removing the diaper; diaper leaks that weren't happening before; the diaper feeling snug around your baby's body; or your baby appearing uncomfortable during diaper changes. When you notice any of these signs, it's time to size up.

Between Two Sizes?

If your baby's weight falls between two sizes, consider your baby's growth rate. If they've just moved into a new size range and are in the lower weight range, stick with the current size. If they're approaching the upper weight limit of their current size or growing rapidly, it's better to size up now to prevent future leaks and discomfort. You can always adjust as your baby continues to grow.

Daytime vs. Nighttime

Many parents find that their baby can comfortably wear one size during the day but may need a larger size or overnight diapers for nighttime protection, especially as they get older and sleep for longer stretches. Longer sleep periods mean more time in one diaper, so extra absorbency becomes important. Don't hesitate to use different sizes for day and night if that works better for your family.

Tape vs. Pants: What to Choose

MamyPoko offers both tape diapers and pants (pull-ups) in all sizes. Tape diapers with adjustable side tapes are ideal for newborns and younger babies who aren't mobile yet. As your baby becomes more active and starts crawling or walking, MamyPoko Pants become incredibly convenient—they're easy to pull up and down, perfect for active play and outings. Many parents also find pants helpful when starting potty training, as they feel more like underwear.

Frequently Asked Questions

Signs that your baby needs a bigger diaper size include red marks around the legs or waist, frequent leaks despite changing regularly, and the diaper feeling tight around your baby's thighs. As a general rule, if your baby is approaching the upper weight range of their current size, it's time to consider sizing up. Trust your instincts as a parent—if something doesn't feel right, try the next size.

Many parents prefer to use the same size for both daytime and nighttime to simplify inventory and routine. However, if nighttime leaks are an issue, consider going up one size or trying overnight-specific products for extended protection during longer sleep periods. Every baby is different, so experiment to find what works best for your family's needs.

MamyPoko Tape diapers have adjustable side tapes and are great for newborns and younger babies who aren't moving much. You can adjust the fit precisely and change diapers while your baby is lying down. MamyPoko Pants (pull-ups) are easier to put on active babies and toddlers who move around more, and they're perfect for when you're out and about or when your child is approaching potty training. Most parents transition to pants around 6-9 months.

Weight is the most important factor for diaper fit, not age. Some babies grow faster or slower than average. Always use your baby's actual weight as the primary guide, and only use age as a secondary reference point. A heavier 3-month-old may need a larger size than a lighter 6-month-old. Regular weight checks at your pediatrician's office help you stay on top of sizing needs.

If your baby's weight falls between two sizes, consider your baby's activity level and how much they've been growing. If they're in the lower range of a size, stick with the current size. If they're in the upper range or growing quickly, it's better to move up to prevent leaks and discomfort. You might also try buying a small pack of the larger size to see if it works better before committing to a full pack.