Pamper’s Baby Diaper Size Chart Guide

Finding the right fit can feel overwhelming, but the Pampers diaper size chart makes it simple. Instead of using age, Pampers uses your baby’s weight to guide sizing, because babies grow differently, and weight is the most reliable indicator for comfort and leak protection.

Quick tips from the Pampers sizing guide:

• Watch for signs it’s time to size up, like red marks, frequent leaks, or a diaper that doesn’t fully cover your baby’s bottom.

• Every baby grows at their own pace, so weight (not age) is the best way to choose.

• Babies move through sizes quickly in the first year, so stock up gradually instead of buying too many in advance.

In the sections ahead, you’ll find details on infant diaper sizes, how many diapers you may need in each size, and how to ensure a proper diaper fit for your little one.

Pampers Diaper Size Chart

Finding the right diaper sizes can feel tricky at first, but a clear Pampers diaper size chart makes it easier. While some parents look for a diaper size by age or even check a diaper size chart by age, this generally isn’t the best method. Babies grow at very different rates, so one 3-month-old may still fit into a newborn size, while another may already need a size 2. That’s why Pampers sizing is based on weight, not age.

Weight is the most reliable guide to finding the right fit, which is why the Pampers size guide and other diaper size comparison charts always focus on pounds or kilograms rather than months. Using a diaper size chart by weight helps you avoid leaks, discomfort, and the need to size up too quickly.

To make things easier, we’ve also addressed two common questions:

• Should you buy a specific number of diapers in each size? Babies grow at their own pace, so it’s often best to wait and see before stocking up on a particular size. For general planning, we’ve included the average number of diapers a baby usually uses in each size on our chart. 

• How long will my baby wear each size? While every baby is different, we’ve included the average number of months a baby usually wears each size. For example, many newborns wear newborn diaper sizes for about a month and a half.

Pampers Diaper Size Chart by Weight

Choosing the right fit is easiest when you use a diaper size chart by weight. Since babies grow at different speeds, the most accurate way to pick the right diaper is by checking your baby’s weight, not their age. That’s why Pampers offers clear diaper sizes and weight guidelines in one simple chart.

*Can vary by baby, age, and individual habits and practice Here’s how to read the Pampers diaper size chart by weight and get the most out of it:

• Weight ranges. The chart is primarily based on diaper sizes by weight to ensure a snug and comfortable fit for your baby. You can determine your baby’s weight at home or during a well-baby visit. For example, a size 1 diaper's weight range is for a baby between 8 and 14 pounds, whereas a size 2 diaper’s weight range is between 12 and 18 pounds. Similarly, the size 4 diaper weight range is ideal for babies weighing 22 to 37 pounds, and size 5 diaper weight is typically for babies over 27 pounds.

• Number of diapers per day. This is an average, and your baby’s needs might vary.

• Duration in each size. This is an estimate of how long your baby will remain in each size before moving up to the next one. Babies grow at their own pace, so always monitor their fit.

• Diaper types. The chart also lists the available Pampers diaper types in each size. Depending on your baby’s needs, whether it’s extra protection during the night or for swimming, you can choose the best option.

Some weight ranges overlap, so it’s helpful to monitor your baby’s fit to know when to switch sizes. Keep reading to learn more about finding the perfect fit, when to size up in diapers, and which Pampers diaper is best for your baby’s needs. Plus, pick-up tips on preventing leaks and blowouts ensure a more comfortable diapering experience.

This chart summarizes available sizes for each product (and includes swim diaper sizes, too) to help you select the right Pampers diapers or pants:

Pampers Easy Up Size Chart

When your toddler starts potty training, pull-up sizes work differently from regular diaper sizes. Instead of standard weight-only ranges, Pampers Easy Ups use clothing-style sizes that overlap to give a comfortable, underwear-like fit.

• 2T–3T: 16 to 34 pounds

• 3T–4T: 30 to 40 pounds

• 4T–5T: 37 pounds and up

• 5T–6T: 41 pounds and up.

Because Pampers Easy Ups are made to pull on and off like real underwear, the waistband is extra stretchy and the sizing overlaps more than in traditional diapers. This creates a more customizable fit that adapts to your toddler’s shape, making potty training easier while still keeping them comfortable and secure.

Pampers Splashers Size Chart

Swim diapers are sized differently from regular diapers, and Pampers Splashers are no exception. Instead of expanding in water like ordinary diapers, Splashers stay light and comfortable, so the fit is based on a blend of weight ranges and flexible design.

• Small (2T–3T): 13 to 24 pounds

• Medium (3–4): 20 to 33 pounds

• Large (4–5): 31 pounds and up.

Because the waistband is stretchy and the core doesn’t swell in water, Splashers offer a more adjustable, swimwear-like fit. That makes them easy to put on and take off, while still keeping your little one comfortable and secure during water play.

Pampers Pure Protection Training Underwear Size Chart

When transitioning out of diapers, Pampers Pure Protection Training Underwear offers a soft option, with 0% Elemental chlorine, fragrance, parabens & natural rubber latex, and sizing that still prioritizes comfort and ease of use.

• 2T–3T: 16 to 34 lb

• 3T–4T: 30 to 40 lb

• 4T–5T: 37 lb and up.

Because these training pants feature a 360° stretchy waistband and easy-tear sides, they provide a customizable fit that adapts to your toddler’s shape, just like underwear, while still offering up to 100% leak-proof protection.

Pampers Ninjamas Size Chart

When nighttime accidents are part of life, Pampers Ninjamas offer a snug and discreet solution designed for older children. They are sized more like underwear and built for confident, dry sleeps.

• S/M: 38 to 70 pounds

• L: 64 to 95+ pounds. 

With a 360° FormFit waistband, Ninjamas adapt to your child’s shape just like regular underwear, offering a customizable fit that moves with them through the night.

Ideal for children aged four to twelve, Ninjamas provide discreet nighttime protection that feels more like underwear—and helps your child stay dry overnight with confidence.

Newborn Diapers

When your baby arrives, the right diaper can help keep them comfortable and dry. Newborn diapers (Size N) are specially designed for babies weighing up to 10 pounds. Many Pampers newborn diapers also feature a small cutout at the front to protect the umbilical cord area and help prevent irritation while it heals during those first few weeks.

Newborns tend to go through a lot of diapers—often up to 10 per day—which means it's a good idea to have a healthy supply ready.

If your baby is born smaller, Pampers also offers three different preemie sizes, providing a snug and protective fit for even the tiniest of babies.

As your baby grows, keeping an eye on their weight can help you decide when it’s time to move from a newborn diaper size to size 1. Many parents find their baby outgrows newborn Pampers within the first month or two, but every baby grows at their own pace.

For more guidance on umbilical cord care or if you’re wondering how many newborn diapers you’ll need, you can read our articles to help you get started or prepare for your baby’s arrival.

How Many Diapers Per Size?

Wondering “How many newborn diapers do I need?” On average, newborns go through up to 10 diapers per day. That adds up to nearly 70 diapers per week—or around 280 diapers in the first month alone.

Every baby is different, though, and diaper usage will change over time. Here’s a realistic way to think about how many diapers per size you might need:

Using our diaper size chart, which aligns sizes with weight ranges, can help you estimate how many diaper sizes you'll need as your baby grows.

For estimating how many diapers per day by age, tracking how many come in each pack, and swapping sizes gradually keeps you prepared without overstocking.

When to Size Up Diapers

Beyond changes in weight, there are several clear signs to help you know when to size up diapers. Choosing the right fit for diapers is about comfort as much as it is about preventing leaks. If you’re wondering how to know when to size up in diapers, watch for these signals:

• If the fastening tapes don't reach the center of the waistband, it's likely time for a bigger size. Conversely, if the tapes overlap, the diaper may be too large.

• If you can't comfortably fit two fingers under the waistband of the fastened diaper, it's time for a bigger size.

• Red marks on your baby's tummy or thighs when removing the diaper indicate that the diaper may be too small.

• If the diaper isn't fully covering your baby's bottom, choose a bigger size.

• Frequent diaper rash, may be because the diaper is too small and doesn’t keep the moisture away from the skin.

• If your baby shows signs of discomfort, such as pulling at the diaper, they might need a bigger size.

These cues can help you decide when to change diaper size or how to tell if a diaper is too small. Paying attention to the fit means fewer leaks and a more comfortable experience for your little one.

If you’re still unsure about how to know when to size up diapers, try using the Pampers size chart as a guide, and remember, every baby grows at their own pace.

How Should a Diaper Fit?

Every baby is unique, so how a diaper fits depends on your little one’s shape as well as their weight. Pampers uses weight ranges as the basis for diaper sizing, since that’s the most reliable way to find a proper diaper fit—not age or gender.

Because weight ranges overlap, you may sometimes choose between two sizes. For example, a size 4 diaper often fits babies 22 to 37 pounds, while a size 5 fits over 27 pounds, and a size 6 fits over 35 pounds. In those situations, a diaper fit guide can help you decide which feels best.

Here are a few ways to check how a diaper is supposed to fit on your baby:

By paying attention to how a diaper should fit on a baby, you’ll help prevent leaks, reduce the chance of blowouts, and make sure your baby stays comfortable throughout the day.

Why the Right Size Matters

When your little one wears the correct diaper size, everything just works better. A proper diaper fit helps keep your baby dry, comfortable, and protected from leaks and blowouts. When the diaper size by weight matches your baby, the diaper performs as intended and may even help reduce skin irritation.

Here’s what could happen if the fit isn’t right:

By choosing the correct size from the Pampers diaper size chart, you’re more likely to have the right fit diapers that keep your little one dry, clean, and comfortable day and night.

Which Pampers Diaper Is Best for My Baby?

As your baby grows and reaches new developmental milestones, their diaper needs will change. Whether your little one is a newborn or an active toddler, Pampers offers a full lineup of diaper sizes and products to support every stage of their development.

Here are some things to consider when choosing which Pampers product to buy:

For Newborns

Because newborns have delicate skin, they need diapers that offer extra softness and protection. The best diapers for newborns are:

• very soft against sensitive skin

• super absorbent to help keep your baby dry

• designed with a cutout so they don’t rub against the umbilical cord stump

• easy to put on and fasten.

You’ll find newborn diaper sizes in Pampers Swaddlers, Pampers Pure Protection, and Pampers Baby-Dry.

For Growing Babies

As your baby becomes more mobile, choosing the correct fit is key to preventing leaks as you transition diaper sizes. For growing babies, choose a diaper that’s

• super absorbent to keep your baby’s skin dry

• designed to move with your baby

• easy to put on and take off.

At this stage, consider Pampers Cruisers 360 and Pampers Swaddlers 360 sizes.

For On-the-Go Babies

When your little one is crawling, beginning to walk, or running easily, you’ll need something you can change quickly. So, with active babies, consider diapers or pants that are

• easy to take off quickly 

• move with your baby as they play and crawl around

• extra absorbent and keep your baby’s skin dry.

For example, you might like our Pampers Easy Ups, Pampers Swaddlers 360, and Pampers Cruisers 360.

For Overnight Protection and Swimming Convenience

Although all Pampers diapers and pants are designed with optimal absorption and leak protection, the following are best for swimming and overnight protection.

• Pampers Swaddlers Overnights offer extra absorption, breathability, and softness for a comfortable snooze. 

• Pampers Splashers are highly absorbent without swelling, so the fit and feel don’t change when your little one is playing in the water.

The Bottom Line

Once you’ve used the Pampers diaper size chart to find the right fit and learned how to change a diaper like a pro, selecting the right diaper size will be effortless. A properly fitting diaper keeps your baby more comfortable, while also reducing the chances of leaks and blowouts. Even with the best fit, accidents can happen, so be sure to stay prepared with our diaper bag checklist for all situations

And don’t forget to treat yourself! By using the Pampers Club app, you can earn rewards for every diaper and baby wipe purchase, making every diaper change a little more rewarding.

_{How We Wrote This Article The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.}