Size matters, so we’ve created the ultimate diaper sizes guide.
Did you know that most diapers are sized by weight and not age? One thing everyone realizes when they become parents is how much babies poop and pee. Diapers are essential, and the right fit is crucial to avoid stained clothes.
Fitting diapers isn’t like buying a t-shirt — you can’t try them on in the store. And let’s not kid ourselves — they’re pretty pricey as well. Just remember, the most expensive brands aren’t necessarily the best.
The table below can help you find the right fit for your baby in case you don’t have a preferred brand yet. However, use it only as a general overview.
Newborn up to first weeks
Up to 10 pounds
Two to four months
8 to 14 pounds
Four to seven months
12 to 18 pounds
Seven to 12 months
16 to 28 pounds
18 to 48 months
22 to 37 pounds
Three years and up
27 pounds and up
Four years and up
35 pounds and up
If you’re expecting, avoid buying diapers in bulk for your newborn. Measurements vary between brands, and your little one will likely grow out of the N and 1 sizes quickly. Buy a small stock and do some testing the first few days following delivery.
Disposable Diaper Sizes
Disposable diapers are one of the most popular choices among new parents (1). They offer the convenience of less cleaning and quick changing.
Pampers Swaddlers come with various features suitable for different ages — they’re even available in a preemie size. The newborn diapers offer an umbilical cord notch, and larger sizes have wetness indicators — here’s your guide.
Huggies Little Movers feature a SnugFit waistband, leak lock system, and contoured shape, as well as double grip strips and a dry touch liner. They also include a SizeUp indicator, so you can easily see when it’s time to change size.
Mama Bear is an Amazon-owned brand. The diapers provide optimal leakage protection, and added comfort with its hypoallergenic, soft, breathable materials. They’re an excellent fit for both day and night — included is a wetness indicator to show you when it’s time to change.
Pampers Pure diapers are free of all chemicals such as bleach, fragrances, and parabens. The material is hypoallergenic and made with cotton-enhanced material, providing a soft texture that’s highly absorbent. They also comprise Pampers leak protection and wetness indicator, keeping your little one snug and dry.
Luvs Ultra Leakguards, with their Nightlock super absorbency, is more than ample as an overnight diaper. They feature triple Leakguards and soft material to keep your little one comfy. The tabs are large so that fastening is secure.
The diapers come with a wetness indicator as well as stretchy sides and cute animal design.
From wet to dry in ten seconds, Huggies Snug & Dry diapers feature a leak lock system as well as a quilted liner. The diapers include four layers of absorbing and protecting material to ensure your baby is as comfy as they can get.
They’re free of bleach, scents, and lotions, which can cause issues with your baby’s skin.
The Honest Super Club Box Diapers are almost too cute to dispose of. They come in various patterns and colors — they’re also soft with high absorbency. The diapers can hold 17 times their weight in fluid, which is locked in to ensure optimal leak protection.
Pampers Cruisers are for active babies — they feature a new stay-put waist with integrated ultra-strong grips. This makes them much stretchier than any other Pampers diaper. And, they have a high absorbency — providing up to 12 hours of protection.
Huggies Little Snugglers are specially formulated to suit sensitive skin — they’re breathable and free of irritants such as scents and parabens. They are soft and come with an additional layer to absorb fluids. The newborn and preemie sizes have an umbilical cord cut out so your baby can heal.
1 to 5 pounds
6 to 9 pounds
8 to 14 pounds
12 to 18 pounds
16 to 28 pounds
22 to 37 pounds
27 pounds and up
35 pounds and up
Overnight Diaper Sizes
Babies don’t hold back, even during the night. At nighttime, extra absorbency is a requirement we can’t ignore, and many times, standard diapers just don’t cut it.
Below, we’ve also included size guides for bedtime underwear if your child often has accidents.
Huggies Overnites help to reduce nighttime changes with their double leak guard, providing up to 12 hours of absorbency. They’re fitted with a SnugFit waistband to prevent leakage, as well as double grip strips for a snug, protected fit. To lock in the wetness, there are embossed inner liners, as well as a breathable outer cover.
Bedwetting can lead to great frustrations both for parents and kids. GoodNites Bedtime Underwear provides a great fit with three different sizes. The underwear sports kid-friendly designs, and they’re highly absorbent of fluids as well as odors.
Honest Overnights come with advanced nighttime protection, which provides 20 percent more absorption than other Honest diapers. The materials are also soft as well as hypoallergenic, and it’s an ultra-thin design, adding to the comfort.
They also sport a cute sleepy sheep design your child may love.
Pampers UnderJams feature a Nightlock system, which traps the moisture, keeping your child and the bedsheets dry. They’re soft and provide a secure fit, while still giving a sensation of underwear. Designs are available for boys and girls.
Seventh Generation Overnight diapers are some of its most absorbent products, capable of protecting your little one all night through. The diapers are fluffy in design with a high capacity core, made from FSC certified sustainable materials.
They have an adorable design of Sylvia the Sheep, with rich colors so you can clearly tell the difference from regular diapers.
22 to 32 pounds
27 to 35 pounds
35 pounds and up
Swim Diaper Sizes
While having fun in the sun, it’s essential to keep your little one’s solids contained. However, please keep in mind that swim diapers aren’t made to absorb fluids — your baby can pee right through them. So remember to only use this type of diaper in the water.
These reusable swim diapers from AlvaBaby are designed to hold your baby’s solids. They don’t have high absorbency since it would make them too heavy and become difficult for your baby to swim. The diapers are adorable to look at, sporting cute ocean-inspired prints.
The swim diapers from Babyganics not only contain your baby’s solids, but they also provide a UPF 50 protection. They feature a sun-sensing system, which changes color as your little one is exposed to UV rays.
Babyganics also use sustainable core material, preventing the diapers from going saggy or swelling due to the surrounding water.
Huggies Little Swimmers provide exceptional protection while enjoying some fun in the water. Huggies utilized a non-absorbent material to avoid swelling when submerged, so your baby can stay active. The diapers have reclosable side tabs, making it easy to adjust as needed.
Pampers Splashers Swim Diapers feature a pull on/tear-off design to make changing easier while wet. They’re fitted with a 360-degree elastic waistband keeping the diaper secure on your little one. They come with an all-over graphic to give an effect of real swimwear.
Langsprit swim diapers offer a waterproof outer layer made of PUL (polyurethane laminate) fabric, which will contain solids passed during swimming. The diapers all include precise stitching and quality fabrics to ensure your little one is comfortable. The material is durable as well — capable of withstanding play, accidents, and multiple washing.
10 to 19 pounds
20 to 40 pounds
Cloth Diaper Sizes
Cloth diapers are the forerunners to disposables. In recent years they’ve made a comeback — proving to be both economical and good for your baby (2).
Keep in mind that many cloth diapers are one-size-fits-all. They come with adjustable snaps.
Kanga Care Lil Joey is an all-in-one cloth diaper, meaning you get both the shell and inserts. It features inner gusset leak protection, and elastic around the legs to prevent any runaways. The diaper is suitable for newborns and has a small cutout for the umbilical cord.
4 to 12 pounds
Rumparooz by Kanga Care Cloth Diaper Cover Size Chart
This is a cloth diaper cover, meaning you must pair it with a fitted or prefold. It’s made from waterproof fabric, keeping all the fluids inside, and features proper elastic around the leg openings. You can use the cover multiple times before it needs a wash — unless a solid slips away.
The OsoCozy Prefolds are made of 100 percent unbleached Indian cotton, put together in a thick lint-free gauze for optimal softness. These prefolds give you eight layers once folded, providing high absorbency. Remember to wash them two to three times before first use to ensure softness and full absorption.
The Rumparooz is a pocket cloth diaper system, consisting of a shell and a set of highly absorbent pads, or soakers. The Rumparooz cloth diaper is to die for — it’s adorable and available in several prints for each style.
BumGenius Freetime is an all-in-one cloth diaper system featuring a butterfly closure mechanism, providing a snug and comfy fit. It’s a no-stuff diaper with included semi-attached inserts, which are easy to change and offer a good solution for children in daycare. The shell is water-proof and ultra-soft.
The GroVia Reusable Hybrid is a cloth diaper shell, which you can pair with GroVia’s snap-in soakers or prefolds. Thanks to the easy snap-in pad system, the GroVia Hybrid can be used by other caregivers such as grandparents or daycare staff. The shell is waterproof and comes with adjustable snaps to accommodate your baby’s ever-changing size.
Alvababy cloth diapers come in pairs of six, each having a polyester shell, made with breathable and waterproof TPU. On the inside, they feature a soft suede cloth that’s highly absorbent, drawing all the moisture away from your baby’s bottom. With each diaper, Alvababy provides you with two, three-layer inserts, made of microfiber.
6.6 to 16 pounds
17 to 22 pounds
23 to 33 pounds
Pull Up Diaper Sizes
Pull up diapers are a great choice when potty training (3). They work like diapers, but your child can pull them up and down similar to underwear. They give your baby a sense of independence and are a confidence booster.
Here are five different brands and their size charts.
Eco by Naty pull up pants are 40 to 60 percent bio-based — it recycles raw materials from Austria. The pull-up diapers have earned a Certified Vegan Logo for containing no animal products and are 100 percent cruelty-free. The diapers feature tear-away sides and are easy for your child to pull up.
Huggies Little Movers Slip-On diaper pants are easy to get in and out of, whether your baby stands or lies down. They have a slim, trim fit with 360-degree stretchy material, keeping the diaper on even during rigorous movement. They have a high absorbency — protecting your little one for up to 12 hours.
These training pants feature a highly absorbent core and perfect fit elastic waist that provides comfort. They are made with breathable cotton that’s soft and flexible to accommodate a moving child. All materials are dermatologically tested to ensure nothing will cause skin irritations or allergic reactions.
The Huggies pull-up training pants are adorable to look at — decked out in Mickey and Minnie Mouse themes. They’re highly absorbent and include easy-to-open sides for quick changes. To help your child learn, the graphics fade when moisture fills the diaper.
Pampers Easy Ups training pants feature a 360-degree stretchy waistband to accommodate your on-the-go toddler.
The pull-up fits like standard underwear but offers diaper-like absorbency. The pants provide ample protection and can easily handle a wet night.
16 to 34 pounds
2T to 3T
30 to 40 pounds
3T to 4T
37 pounds and up
4T to 5T
Tips for Sizing Diapers
One thing I learned as a first-time mom was that giant blowouts aren’t supposed to happen. After multiple attempts on tightening the diaper and using fitted shorts, I was finally told the diapers I was using were the wrong size. Here are five tips that helped me:
Read the box: This is obvious, but it’s still essential to do since babies vary in shapes. Two babies of similar weight won’t necessarily suit the same diaper. Manufacturers base diaper sizes on average-sized babies — I had my little one in a larger size way before he reached the previous diaper’s weight limit.
Regular blowouts and leaks: If you often experience leaks and blowouts, it’s a clear indicator the diaper is too small. It’s unable to contain your baby’s waste, and perhaps even too short at the back, providing little coverage for the bottom.
Difficult to close: Having to stretch the closures excessively is another sign the diaper is too small. This also isn’t comfortable for your little one — this isn’t the age for waist training — let the chunky tummy breathe.
Red marks: Red marks anywhere on your baby is never a good sign. Inspect your baby’s thighs where the elastic sits — if there’s any redness, move up a size. Leg openings are supposed to sit tight, but should never create marks.
Test drive: We highly recommend you buy a small supply of different sizes from various brands if you’re a first-time parent. This way, you test drive which size is best suited to your little one without wasting a ton of diapers or cash.
Being a parent is like a rollercoaster — some days are amazing, and others require some patience. When it comes to diapers, size matters — they shouldn’t be too tight, yet must still be capable of preventing a blowout. Most diaper sizes are categorized into weight classes, based on average-sized babies.
Use our diaper sizes guide to get a general idea. Then test the waters a bit to see which brand suits your baby the best.
Shannon Serpette is an award-winning writer and editor from Illinois, who regularly contributes to newspapers, magazines, and websites. As a mother of two, she loves to write about parenting issues and is dedicated to educating other parents at every stage of their child's development.