A New Parent's Guide to Estimating How Many Diapers You Need and What They'll Cost

A New Parent's Guide to Estimating How Many Diapers You Need and What They'll Cost

Throughout their first few years of life, your baby will poop and pee pretty much all day long. The sheer amount of soiled diapers can be overwhelming to new parents—and cost several hundred dollars annually. Stocking up can save you money in the long run, but if you're new to parenthood, you're probably wondering a few things.

First being, "Um, how many diapers does a baby go through in a day?" Second, "how many diapers should I buy at once?" The exact answers are hard to pinpoint for three reasons:

  1. On average, newborns go through about eight-12 diapers per day. But each infant is different so you'll have to learn as you go how predict how much your newborn will need changing.

  2. Diaper sizes are based on weight instead of age. Each baby grows at a different rate, so it's nearly impossible to predict which sizes they'll need at 3 months old, 18 months old, etc.

  3. Diaper demands adjust as babies grow up. Your child will need the most diapers during the newborn stage. By the time they reach potty training age, they may only need four or five daily diapers.

That said, if parents want to estimate how many diapers they need, it's best to break everything down by size. Most manufacturers create diapers in "Newborn" size (10 pounds and under) to size 6 (35 pounds and over). Some brands, like Huggies and Pampers, also make "Preemie" diapers for babies less than 6 pounds, while others offer size 7 diapers for toddlers 41 pounds and over.

As with most things, you can save money by buying diapers in bulk. "Boxes" contain more diapers than "packs"—for example, a size 1 pack usually has 40 diapers, while a size 1 box contains about 164 diapers. Boxes usually have a lower price per diaper, but do your research and budget accordingly.

baby wearing diapers smiling with open mouth
baby wearing diapers smiling with open mouth

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Diaper Size Buying Guide

Here's a size guide to estimate how many diapers you'll need—but remember to take it with a grain of salt, since every baby is different. Also note that as diaper sizes increase, you'll generally get fewer diapers per box. For example, you can expect to get 164 diapers in a size 1 box, but only 136 diapers in a size 3 box.

Premie (6 pounds and under): Generally, only babies born prematurely need this diaper size. There's no way to predict whether your baby will be born early—and what size they will be—so plan to purchase these diapers as needed.

Newborn (10 pounds and under): Young babies grow fast, so they'll graduate from newborn diapers after a few weeks. Plan to go through about eight-12 diapers per day, which equates to about one or two boxes (assuming each box contains 140 diapers). Note that many parents receive newborn diapers from the hospital too.

Size 1 (8 -14 pounds): Most babies need size 1 diapers until 4 months of age, and they'll soil about 8-10 diapers each day. Therefore parents can plan to buy around three to four boxes, based on 164 diapers per box.

Size 2 (12-18 pounds): These are commonly used by babies 3 to 8 months old, who produce eight or nine dirty diapers each day. Expect to buy anywhere from three to five boxes, with 142 diapers in each one.

Size 3 (16-28 pounds): Now's the time when stockpiling starts to come in handy. A wide range of babies need size 3 diapers—in fact, they're commonly used by infants from 5 months to 24 months old. At this age, babies go through six or seven diapers each day, so you'll need about seven or eight boxes, assuming there's 136 diapers per box.

Size 4 (22-37 pounds): Size 4 diapers usually cater to babies between 18 months and 36 months, who soil about five to seven diapers each day. Because many babies don't need size 4 diapers until they're almost 2, many parents choose not to stock up in the early days. Expect to use anywhere from two to five boxes of these.

Size 5 (27-35 pounds): Size 5 diapers fit toddlers 27 pounds and over; kids generally reach this weight around 3 years old. Plan to buy and use these diapers as needed.

Size 6 (35 pounds and over): As the biggest size many brands make, size 6 diapers are usually reserved for those older than 4. Plan to buy and use these diapers as needed.

Size 7 (41 pounds and over): Some brands, such as Pampers, also make size 7 diapers for older toddlers. Once your child reaches 41 pounds, gauge the situation and buy these diapers accordingly.

Here are some important things to keep in mind when estimating how many diapers you'll need:

  • Most parents have a preferred diaper brand, and figuring it out takes some trial and error. You might want to hold off on stockpiling until you test a few different options.

  • Some diapers brands run smaller than others. If you're worried about fit, read product reviews or ask other parents about their experience.

  • Some baby weights overlap between different diaper sizes. If you don't know which size to buy, consider your little one's body structure. A chubbier baby may need the bigger option, while a longer, skinnier baby might fit best in the smaller one. Also note that smaller sizes are generally cheaper.

How Much Do Diapers Cost?

Disposable diapers aren't cheap. And while the cost depends on many factors, including brand and package size, parents can expect to shell out a sizable sum over the years.

Here's a general breakdown: The average diaper costs anywhere from $0.20 to $0.30. Assuming your baby uses 2,500–3,000 diapers in their first year of life, you can expect to spend about $500-$900 on an annual supply. This doesn't count the cost of other diapering supplies, such as wipes and a changing table. Buying eco-friendly products also raises the price by a few hundred dollars.

Of course, there are plenty of ways to save money on diapers. Try using coupons, finding discounts online, buying in bulk, stockpiling whenever you see diapers at a low price, and testing out lower price options. Some parents also believe that cloth diapers save money, but it's more work to wash the diapers after each use (or use a diapering service). You can learn more about cloth diapers here.