How Long Are Babies in Newborn Diapers?

Newborn babies go through a lot of diapers. You may be tempted to run out and buy several economy-sized boxes of diapers before baby comes to stock up to save a little money in the process. If you do, you may be disappointed to find that your baby outgrows the newborn size so quickly that you have many diapers left over. Exactly how long your baby will spend in newborn diapers depends on how much he weighs at birth and how quickly he grows. Understanding the averages can help you estimate how many newborn diapers you will need.

Weight Range

Before you can understand how long your baby will wear newborn diapers, you have to know what size babies newborn diapers accommodate. Most newborn diapers are made to fit babies weighing up to 10 pounds, although some brands may go up to 12 pounds. adds that some brands have overlapping ranges, such as newborn diapers that go up to 12 pounds and size 1 diapers that are for babies weighing 8 to 14 pounds.

Average Weights

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The Average Weight of a Newborn

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Every baby is different, and some might be born weighing 6 pounds, while others might come in at 10 pounds. According to the Centers for Disease Control and Prevention, the average weight for newborn babies is just under 8 pounds, for both boys and girls. The average baby reaches 10 pounds at 1.5 months old. At 10 pounds, most babies are ready to move on to a size 1 diaper, depending on the brand. Babies in the third percentile for weight won't reach 10 pounds until approximately 3 months.

Premature Babies

Babies who are born premature -- or before the 37th week of pregnancy -- are usually born at much lower weights. Even babies who are not born prematurely can be born at a low birth weight. The March of Dimes says 1 in 12 babies will be born weighing less than 5 pounds 8 ounces. Babies born prematurely or with low weight may not fit newborn diapers when they are born. It may take them several weeks or months to fit newborn diapers, depending on how low their weight at birth is and how fast they gain weight. Once they fit into newborn diapers, they should be able to wear them for one to three months, just like babies born at average weights.

Larger Babies

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How Much Weight Do Newborns Gain?

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Some babies are born at higher weights and may never wear newborn diapers at all. According to CDC data, babies in the 95th and 97th percentile on growth charts are born weighing at or near 10 pounds. That means that only 3 to 5 percent of babies are born at that weight. These babies may fit newborn diapers for a few days or even a week, but most parents find it easier to skip right to using size 1 diapers.