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Diaper Calculator

Our calculator uses data provided by the CDC's Baby Growth Charts and the diaper manufacturer's sizing and usage charts. CDC data is based on the average growth rate of a child.

However, not all children are the same. Please use the data provided as a general estimate to help you plan your diaper purchases.

Disposable Diaper Calculator Refresh

Add your baby's age & weight to calculate the number of diapers you will need during your first year. If you're still pregnant, please estimate your baby's weight.

Enter birthday instead
Estimate baby's weight

How many diapers per day?

0-3 MONTHS10
3-6 MONTHS8-10
6-9 MONTHS6-8
9-12 MONTHS6-7
12-18 MONTHS5-6
18-36 MONTHS4
Diaper usage is based on your baby's age. The younger your baby. the more diapers will be used per day.

What size diaper to choose?

SIZE 18 - 14 LBS
SIZE 212 - 18 LBS
SIZE 316 - 28 LBS
SIZE 422 - 37 LBS
Diaper sizes are based on your baby's weight.

Here's a helpful chart of expected weight gain over the next 6 months. Hover over the chart for more details.

Amazing Savings For New & Expecting Parents

How Many Diapers & What Size Do You Actually Need?

Welcome to our free, easy-to-use Diaper Calculator. It will help you estimate how many diapers your baby needs, what size diaper per stage is expected from birth until potty training, your total costs, and a detailed price comparison between the most popular diaper brands.

Diapering can get complicated, which is why moms and dads have so many questions. These are just a few commonly asked diaper questions from regular moms, like you:

  • How many newborn diapers do I need? / How many diapers do I need?
  • What diaper size do I need?
  • How many diapers per day?
  • When to go up a size in diapers?
  • How much do diapers cost?
  • How many diapers does a baby use in a year?

The diaper calculator will help you answer this, and other questions you may have.

The calculator is easy to use. Simply add your baby’s details, and the diaper calculator will offer estimates based on CDC data and big brand diaper companies, like Pampers and Huggies.

If you have further questions, or you have found a glitch in our calculator, do let us know in the comments below. We are continually tweaking it to make sure it is an accurate and helpful tool for moms and dads.

A new mom’s guide to diapering like a pro

Diapering seems so easy at first glance, but it can get confusing and frustrating. Here are a few helpful posts to help you figure things out.