What Size Diaper Does My Baby Need? 7 tips to help you know when it's time to size up

It’s no question: diapers are a necessity when you have a baby in the house, and many will argue it’s hard to beat the convenience of disposable diapers. As new moms know all too well, babies go through A LOT of diapers! So you stock up – and suddenly your baby is outgrowing her current size.

New moms may not realize diapers are sized based on a baby’s weight, not on his or her age. Like many products, sizing and fit can vary by brand and by your baby’s body shape. Babies that are long and lean may stay in a smaller diaper size longer than a baby of the same weight that is shorter and a little chubbier. A good rule of thumb is to check the size guidelines on your preferred diaper brand’s box and follow these 7 tips to help you know when it’s time to size up.

• Baby’s weight: If your baby is on the upper end of the suggested weight range for your favorite brand of diaper, he or she may need to move up to a larger size. But take into consideration your baby’s body type. If she’s long and lean, she may stay in the smaller size a little longer.
• Frequent leaks or blow outs: If your baby’s diaper is often leaking (day or night) or your baby begins having frequent blowouts in a diaper brand that has been working well for you, it may be time to try a larger size.
• Coverage: If the diaper looks small or no longer fully covers your baby’s bottom, it may be time to size up.
• Red marks or chafing: If you notice red marks or chafing around your baby’s thighs, groin, hips, or waist, it may be time to move to a larger diaper size.
• Hard to secure or gapping tabs: You should be able to connect the tabs on the diaper without tugging or pulling. If it’s hard to do so, or if the tabs keep popping open, it may be time to size up.
• Tight at the waist: You should be able to insert two fingers between the diaper and your baby’s skin. If the diaper is too tight to do that, it may be time to move to the next size.
• Baby seems uncomfortable: If your baby seems uncomfortable – possibly tugging at his diaper or trying to pull it off – it may be time to size up.

Bonus tip: Swim diapers are sized differently than regular diapers. They are generally sized S, M, and L with those sizes usually corresponding to diaper sizes 3, 4, and 5. Check the labels and guidelines on swim diaper packaging to help determine the right size.

Babies can change diaper sizes more quickly than you think. A newborn – while going through a lot of diapers – may only spend a month in a newborn or size 1 diaper, but an older baby could stay in a size 4 or 5 for around six months. Pampers has a size and weight chart guide on its website to give you an idea of how many diapers your baby may go through in a day and how long he may spend in each size. If you have stocked up on one size only to find your baby is ready to move up, you can donate extra diapers to a local diaper bank who can get them to moms in need.

At One by One, we mentor and educate new moms to parent well. Each month we share tips for new moms. If you or someone you know would like to have a mentor to help her through her pregnancy and baby’s first year, you can apply for a mentor here. If you have a heart for helping new moms, join us as a mentor! Learn more here.