Are Diaper Sizes Universal?

Finding the right fit for your baby

Selecting the right size diaper isn’t always obvious, primarily because there is no universal measurement system or size chart used by all diaper brands. To add to the complexity, some companies use variable sizes or go up to a different maximum size–often labeling the largest size as suitable for all infants over a specific weight.


It’s widely thought that finding diaper sizes by weight is the best solution, and a more accurate indicator, as every baby and toddler grows at a different speed.


Today, we'll share some tips for selecting diaper sizes for a registry, ensuring your regular delivery of superb-quality diapers is comfy, gentle on your baby's skin, and the right size to prevent leakages.


Why Is it Important to Select the Right Size Diaper?


While occasional leaks and blowouts are an inevitable part of life with a baby, they can be kept to a minimum by ensuring your little one is wearing a diaper with good absorbency and the best possible fit.


Diapers that are too tight can cause irritation and discomfort, especially because babies have more sensitive skin than adults. A diaper that rubs or chafes against the gentle skin on your baby’s thighs and waist can create marks, discomfort and even restrict movement.


Likewise, a diaper that is too big won't prevent leaks and can contribute to more accidents than you might expect because an overly large diaper will have gaps and loose panels around your baby's body.


Signs That Your Baby Needs an Alternative Size Diaper


Fortunately, there are lots of indications to help parents spot when their infant has a diaper that is too big or small. Here are some things to look out for:


  • Gaps around the legs and waist
  • Tabs that overlap or that are difficult to secure on the edges of the diaper
  • A waistline that is more than two finger widths below your baby’s belly button or that leaves red marks and indents
  • A higher frequency of leaks and blowouts, or even tears in the fabric of the diaper (a common issue for active babies or those who move around a lot during sleep)

If you are a new parent or are unsure whether your baby is wearing the right diaper size, you can also check their weight against our helpful size chart. We’ve created this based on averages, with weight thresholds to show the typical points at which a growing infant will need the next size up.


However, it’s important to reiterate that every baby is different, and you might decide to stick with your current diaper size for a little longer or size up sooner. It's all about choosing the right fit that is comfy, secure, and snug for your child without leading to blowouts and leaks.


How to Pick the Perfect Size Diaper


The best option is usually to consider your baby's weight rather than age. Children grow at dramatically different speeds, so one infant might progress through two or even three diaper sizes over just a few weeks. Another might be content and happy in the same size diaper for several months, and both are perfectly normal.


A diaper that is just right won't sacrifice comfort or absorbency and will ensure your baby feels secure as they start to crawl, stand, and walk. The ideal fit looks like this:


  • The tabs don’t overlap or need extra tension to land in the middle of the diaper.
  • The legs and waist sit nicely against your baby's skin but don't dig in or irritate.
  • The waist is snug and sits no more than two to three fingers below your infant’s belly button. If their diapers start to sit lower on your little one's waist, this is a sign that you might need to consider sizing up.

If you have doubts, aren't sure of the equivalent Coterie size compared to a brand you've previously used, or would like some advice, we’re always here to help at hello@coterie.comOpens in a new tab.!