What Size Diapers Do Newborns Wear?

Wondering what size diapers to buy for your newborn? Get all the info you need on newborn diaper sizes, including how many diapers you can expect to go through in those first few weeks.

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Diaper Sizes

Diaper sizes for newborns is often determined by weight. They will generally fit a baby that is between 8-14 pounds, and there are a few different size options for this weight range. The most common newborn diaper sizes are 1 and 2. Newborn size 1 diapers are for babies 8-10 pounds, and newborn size 2 diapers are for babies 11-14 pounds.


Preemie diapers are for very small babies, usually 3 to 5 pounds. Sometimes premature babies are born as small as 1 or 2 pounds. Special preemie diapers have an umbilical cord cut-out for newborns that need it. These preemie diapers are smaller in every way, with smaller tabs and a smaller rise.

If your baby is in the hospital, the nurses will help you decide when they’re ready to move up to aSize 1 diaper. Once they go home, you’ll still want to keep them in preemie diapers until they reach at least 5 pounds.


Most newborns will wear Size 1 diapers. Newborn-sized diapers are designed to fit babies up to 10 pounds, and they have a soft, flexible waistband and leg openings that provide a comfortable fit. If your baby is on the smaller side, you may want to try Size 0 diapers.

Size 1

Most newborns will be in size 1 diapers. A good rule of thumb is that if your baby is under 10 pounds, they’ll need size 1 diapers. Once a baby gets over 10 pounds, they’ll likely move up to size 2. But it’s not always that simple – some babies who weigh less than 10 pounds may still need size 2 diapers, and some babies who weigh more than 10 pounds may still need size 1. If you’re unsure of which size to use, ask your baby’s pediatrician.

Size 2

Size 2 diapers are meant for babies who weigh between 12 and 18 pounds. They’re often called “starter” diapers because they’re the size that most babies wear when they first start using diapers.

How to Choose the Right Size

Newborns generally start out in size newborn diapers. These diapers will fit a baby up to 10 pounds. If your baby is on the small side, you may be able to get away with using size one diapers. If your baby is on the larger side, you may need to move up to size two diapers.


Use your baby’s weight to determine the size of diaper they need. Newborns will usually be in the smaller range of sizes, and then move up to the larger sizes as they gain more weight.
-If your baby is between 8-14 pounds, they will need size 1 diapers.
-If your baby is between 15-20 pounds, they will need size 2 diapers.
-If your baby is between 21-26 pounds, they will need size 3 diapers.
You should always buy diapers based on your baby’s current weight rather than how much you think they will weigh in the future. It’s better to have a diaper that’s a little too big than one that’s too small and doesn’t provide enough coverage.


Length is the first thing you need to think about when picking a size for your baby. The diaper should come up to at least the baby’s belly button, and no higher than their back. If the diaper is too long, it can sag and cause leakage. Too short, and it will dig in and be uncomfortable.

The second thing you need to think about is weight. Newborns come in all different sizes, so you’ll want to make sure you have a size that will fit your baby even if they lose or gain a few ounces.

Here is a general guide to help you pick the right size for your newborn:
-If your baby is less than 10 pounds, you will want to use size 0-3 diapers.
-If your baby is between 10-15 pounds, you will want to use size 3 diapers.
-If your baby is between 15-20 pounds, you will want to use size 4 diapers.

Other Considerations

Once you’ve decided on a brand, you’ll also want to consider the other factors that go into choosing the right size diaper for your baby. In addition to weight and stage, you’ll also want to take into account factors like leak protection, absorbency, and comfort.

For leak protection, you’ll want to make sure the diaper has a snug fit around your baby’s waist and legs. You’ll also want to choose a diaper with enough absorbency to last through the night or a long car ride. For comfort, you may want to consider diapers with softer materials or special features like wetness indicators.

When to Move Up a Size

The biggest mistake parents make is keeping their baby in one size too long. Usually because they don’t want to spend the money on new diapers, or they don’t realize the baby has outgrown them. Wearing the right size diaper is important for a few reasons.


If your baby starts leaking through their diaper, it’s probably time to move up a size. Newborns typically need to be changed every two to three hours, but some may need to be changed more frequently. As your baby grows, they’ll be able to hold their bladder for longer periods of time and will need to be changed less often.

There are a few things to look for that may signal it’s time to move up a size in diapers:

-Diapers are leaving red marks on your baby’s skin.
-Diapers are consistently leaking.
-Your baby is uncomfortable in their diaper.
-Your baby is between sizes (for example, if they’re in between newborn and size 1).

If you’re not sure what size diaper to buy, most brands have size charts that can help you choose the right fit for your baby.

Diaper is Too Snug

If the diaper is too snug, it can lead to leaks. You’ll want to move up a size if you notice any of the following:
-Red marks on your baby’s skin caused by the diaper being too tight.
-Diaper leaks around the legs or waist.
-Your baby seems uncomfortable in the diaper.

Diaper Looks Too Big

You may feel like you made a mistake when you see how big the diaper is, but that’s perfectly normal. Newborn diapers are designed to fit snugly around your baby’s thighs and bottom, with plenty of room to grow. In fact, you may find that you need to use the smallest setting on the tabs at first. If the diaper feels too large, you can try using the smaller setting on the tabs or folding down the top of the diaper to create a snugger fit.


In conclusion, you can expect your newborn to use anywhere between 2-5 diapers per day. It is best to have a few different sizes on hand, as you never know when your little one will have a growth spurt. Hopefully this guide has helped demystify the process of choosing the right size diaper for your newborn!

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