How Long Do Babies Use Newborn Diapers? (By Age, Weight, Length)

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Stocking up on newborn diapers for your expecting baby may seem like a no-brainer, but knowing how many newborn diapers you need can be tricky. How long do babies stay in newborn diapers?

The length of time a baby wears newborn diapers depends primarily on their weight. On average, babies spend just over one month in newborn diapers; however, smaller babies may wear them for several months while larger babies may skip them altogether. For most brands, size 1 diapers can be worn at 8 pounds, providing some overlap between sizing.  

Continue reading to learn more about newborn diaper sizing, stocking up on diapers, and when to size up. 

How long do babies stay in newborn diapers?

Your baby’s weight is the biggest factor in determining which size of diaper will provide the best fit.

Most babies will fit into newborn diapers at birth, although a few will require either preemie diapers or go directly into size 1. The length of time your baby wears newborn diapers can vary greatly depending on their birth weight, sex, and overall growth rate. 

According to the University of Michigan, the average birth weight for babies is around 7.5 pounds, but anywhere between 5.5 and 10 pounds is considered normal, and fewer than 3% of babies weigh more than 10 pounds at birth. In the first five days, newborns may lose around 8 ounces (or half of a pound), but they typically gain it back in their second week of life. Babies go on to gain about 6 ounces (0.375 pounds) a week until they are six months of age. 

Here is a look at what your baby’s growth pattern may look like in the first six weeks based on their birth weight.

Growth rate by birth weight

Birth Weight
(lbs)
Week 1
(lbs)
Week 2
(lbs)
Week 3
(lbs)
Week 4
(lbs)
Week 5
(lbs)
Week 6
(lbs)
5.555.55.96.36.67
65.566.46.87.17.5
6.566.56.97.37.68.5
76.577.47.88.18.5
7.577.57.98.38.69
87.588.48.89.19.5
8.588.58.99.39.610
98.599.49.810.110.5
9.599.59.910.310.611
109.51010.410.811.111.5

Aside from their weight, your baby’s length and overall proportions may also come into play, especially when your baby is close to sizing up. Since babies vary so much in size, age is never a major consideration. 

Most diaper brands have a two-pound “buffer zone” where babies can fit into both newborn and size 1 diapers. Though size 1 diapers are less likely to go to waste, most newborn diapers have an umbilical notch, which prevents irritation of the umbilical stump. Some parents find this especially helpful in the first few weeks. 

Newborn diaper weight

Diaper brands base their sizing on a baby’s weight. According to Pampers, this provides the most accurate fit for babies

Seemingly all newborn diapers fit babies up to 10 pounds; however, there is some variation in size 1.

Here are some popular diaper brands and their weight ranges for newborn and size 1 diapers: 

Weight Ranges for Common Newborn Diapers

BrandNewborn Size (N)
Weight Range
Size 1
Weight Range
Pampers< 10 lbs8-14 lbs
Huggies≤ 10 lbs< 14 lbs
Honest< 10 lbs< 14 lbs
Hello Bello< 10 lbs8-12 lbs
Up & Up< 10 lbs8-14 lbs
DYPER< 10 lbs6-16 lbs
Luvs< 10 lbs8-14 lbs
Earth's Best< 10 lbs8-14 lbs
Seventh Generation< 10 lbs8-14 lbs
Kirkland Signaturen/a8-14 lbs
Cuties< 10 lbs8-14 lbs
Thrive Market0-10 lbs8-14 lbs
Coterie< 10 lbs8-12 lbs
Bamboo Naturen/a4-9 lbs
Natural Blossomn/a> 11 lbs

Newborn diaper length

Though your baby’s length may be a determining factor in what diaper works best for them, no popular diaper brands provide length measurements in their sizing charts. 

If you have a particularly long baby, you may find that some newborn diapers are too short for their torso. Size 1 diapers may provide a better fit around the waist and legs since they are made for bigger babies. 

Ultimately, finding the best diaper for your little one may come down to choosing the right brand. All brands have a slightly different fit and some may be better suited for your baby’s proportions.

Looking for the best diapers for long babies? Check out this post!

Newborn diaper age

Though the term “newborn” implies a specific age, diaper sizes are not actually based on a baby’s age.

Newborn babies vary so much in size, and they continue to grow at their own pace. Though some resources provide correlations between diaper sizes and age, these are ultimately tied to the average weight of babies at that age.

For instance, babies will spend a little over a month in newborn diapers, based on the average weight of a newborn (7.5 pounds). 

How many diapers is normal for a newborn?

Tracking your newborn’s wet and poopy diapers will help you ensure that they are getting enough milk or formula.

On their first day, newborns may only need a few diaper changes. By the time they are five days old, they will be going through around nine diapers a day.

Here is a breakdown of the number of diapers you can expect to go through in the first days of their life.

How Many Diapers Newborns Will Go Through

AgeNumber of
Wet Diapers
Number of
Poopy Diapers
Total Number
of Diapers
Day 11-212-3
Day 22-424-6
Day 32-435-7
Day 44-53-47-9
Day 5
and onward
6+3-49+

Your baby will continue to use around 9 diapers a day until they are two or three months old when their bladder can hold their pee for longer. 

Can premature (preemie) babies fit newborn diapers?

While most newborns will be able to wear Newborn-size diapers, there are some babies who will be too small for the standard size.

Most diaper brands do not specify a minimum weight for their newborn diapers; however, they may be too big for some premature babies. If there is substantial gapping at the waist or legs, or your baby experiences frequent leaks, their diapers may be too large.  

If your baby is too small for newborn sizes, Pampers offers three sizes of preemie diapers that may provide a better fit. 

Pampers Preemie Diaper Sizes

Diaper SizeWeight Suggestion
Pampers Swaddlers Preemie Diapers P-1 (P-S)< 6 lbs
Pampers Swaddlers Preemie Diapers P-2 (P-XS)< 4 lbs
Pampers Swaddlers Preemie Diapers P-3 (P-XXS)< 1.8 lbs

How many newborn diapers do you need?

The number of newborn diapers you need will depend on your baby’s birth weight and subsequent growth. Additionally, since there are about two pounds of overlap between sizes, parents get a little bit of wiggle room to decide when to size up. 

Based on an average of nine diaper changes a day, here is an estimation of how many weeks you can expect your baby to use newborn diapers and how many 140-count boxes of newborn diapers you may go through based on birth weight.

Birth WeightWeeks in Newborn DiapersBoxes (140-count) Newborn Diapers
5.5 lbs9-144-6
6 lbs7-133-6
6.5 lbs6-113-5
7 lbs5-102-5
7.5 lbs3-91-4
8 lbs2-70-3
8.5 lbs0-60-3
9 lbs0-50-2
9.5 lbs0-30-1
10 lbs0-10-1

How many newborn diapers should I stock up on?

Though it’s important to prepare for your little one’s arrival, stocking up on newborn diapers can be risky.

Many babies grow out of them very quickly, so they are easy to over-purchase. Many people advise getting no more than one or two boxes of newborn diapers. 

If you are planning on stocking up, knowing whether you are expecting a small, average, or big baby may help you decide how many newborn diapers to get.

Here are a few ways healthcare providers can estimate your baby’s weight:

  • Symphysis-fundal height (SFH) is a measurement of the mother’s abdomen (pubic bone to fundus) which corresponds to fetal growth. 
  • Ultrasound measurements taken by a sonographer can roughly predict birth weight.
  • Gestational age plays a large role in a baby’s birth weight; for instance, a baby born at 37 weeks will likely be smaller than a baby born at 41 weeks. 
  • Pregnancy complications may affect a baby’s birth weight. For instance, expecting mothers with gestational diabetes often have larger babies. 

If you are purchasing diapers before your baby arrives, it’s always good to familiarize yourself with your store’s return policy.

Check out my articles on returning diapers to Target and returning diapers to Walmart for more information. 

Can you use size 1 diapers on a newborn?

If your baby is on the larger size of average, you may not need Newborn diapers at all.

Though sizing depends on the brand, most size 1 diapers have a weight range starting at 8 pounds. This means that some newborn babies can skip newborn diapers entirely. With 2 pounds of overlap between sizes, many parents may pick which size is most convenient. 

Some parents choose to use newborn diapers because they offer an umbilical cord notch. This is a cut-out that prevents the diaper from rubbing against your baby’s healing umbilical stub. Though this is a helpful feature, folding your size 1 diapers or manually cutting out a notch can offer the same effect.   

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