How Long Twins Will Wear Newborn Clothes | Sizes Demystified

Congratulations on expecting twins!

Being a newly expecting mother can find itself to be challenging at times. There are so many questions and few answers. Motherhood doesn’t exactly come with a manual guide, and babies are not exactly carbon copies. 

Being a mom of two amazing little girls, I can confidently say….I’m still learning too. Don’t worry, though, it helps to hear from other moms with some experience raising little ones of their own. 

So here is some insight into things I have come to learn in raising my own kiddos and things I have picked up from other sources and mothers along the way. 

How long do twins wear newborn clothes?

Birth size, growth rate, and clothing brand will all affect how long newborn clothes will fit twins. Generally, newborn clothes will fit for the first 4-6 weeks, though this is only an estimation. Clothing may shrink, and babies may grow at different rates, so plan on having larger sizes ready.

Taking a deeper look at the different variables will help you make the best decision on how many clothes in each size you will need for your newborn babies.

This will help you fully prepare for when your little ones are born. 

Twins and Newborn Clothes

Clothing a newborn gets expensive. Clothing twins? Well, you better pay close attention. Let’s start by looking at one of the most important factors when clothing your babies – their weight.

Average Weight of Newborn Twins

The average birth weight for a newborn baby is about 7.5 pounds, whereas the average birth weight for twin babies is about 5.5 pounds. 

Twins are born generally smaller than singletons (1 baby), and according to the CDC, roughly 50 percent of twins weigh less than 5.5 pounds (or 2,500 grams), compared to only 6 percent of singletons. 

Do Newborn Twins Need Preemie Clothes? 

I would definitely recommend getting a couple outfits in preemie sizes just because twins tend to have a lower birth weight. 

Preemie size goes up to 5 pounds. However, you could hold off and wait to buy preemie clothes until you are closer to term and see how big your babies are. 

If your babies are growing well and their weight is close to or at 5 pounds before giving birth, then you won’t need them. If they are on the smaller side, it is definitely a good idea to invest in them, just in case.

How Many Clothes Do Newborn Twins Need? 

Newborns need a lot of clothes, even more so if they are being born during the fall or winter. Here is a little breakdown of just how many clothes they could use, per baby, to give you an idea. 

Mom Tip: Consider having 2 dressers. One for the clothes they would be wearing right then and one for the clothes in the next few sizes up. For example, the extra dresser would have drawers for 0-3 months, 3-6 months, and 6-9 months with bigger socks, hats, and larger bibs in the bottom. 

Onesies were my favorite; make sure you have a bunch of these. The onesies will give your babies that extra warmth they need, and I found them to be a lot easier to snap in the middle of the night than the pajamas.

Outfits. Ah now, who doesn’t want every single cute outfit they find in the baby section at Target! In all reality though, we don’t really need all of them… so I settled with half. 

Outfits are too darn cute, and of course they need a good amount but not as many as we set our eyes on. 

Depending on how often you plan to do your laundry, I would plan how many outfits you need around that. Also, take into mind that your kiddos will have blowouts, spit-ups, and once in a while, pee all over while in a mid-diaper change.  

How many socks do you need? A million. You will lose one sock in each load of laundry and the other at daycare, the grocery store, or Nana’s. You can never have too many of these. 

You don’t need too many hats and mittens. I would say about 8-12 is a good general number for hats, and what type of hat depends on the weather. 

For gloves, I would estimate about 4-6 pairs. My kids never kept their gloves on, but they do come in handy to help make sure they aren’t scratching their faces with their little fingernails. 

Bibs — you need many of these, especially if your baby spits up a lot. I feel like I went through roughly 3-4 a day. They also help save the cute clothes underneath, and some outfits come with matching bibs! 

How Long Are Newborns Typically in Newborn Clothes? 

According to Kid’s Health, babies can gain about 1-1.5 inches in length and about 2 pounds within the first month alone. Ideally, if you have a smaller or premature baby, then they will still be in newborn clothes until approximately halfway through the second month, while a baby who was born bigger could be out of newborn clothes in the first month. 

In my experience, my girls were both 4 pounds12-13 ounces and wearing preemie for the first week or two, newborn for the first couple months, and then had finally grown out of newborn clothes probably closer to the end of the second month. 

Make sure you are watching those 100% cotton labels, and if you’re unsure, go for the bigger size. The rule of thumb is always to get the bigger size.

If you shrink it too much in the wash, you just wasted money, and if it’s too big, they can always grow into it.

When To Move a Size Up in Baby Clothes? 

You will be able to see when it’s time to move up a size in baby clothes. When you see some clothes fitting more snugly, bring out some in the next size up, and see how they fit. 

Baby Clothes Size Chart

Below is a size chart to help understand a general guideline for clothing sizes for babies.

Clothing SizeWeight Height
PreemieUp to 5 lbs.Up to 17 in. 
Newborn5-8 lbs.17-21 in.
0-3 Months8-12 lbs. 21-24 in.
3-6 Months12-16 lbs.24-26 in.
6-9 Months16-20 lbs.26-28 in.
9-12 Months20-24 lbs.28-30 in.
12-18 Months24-28 lbs.30-32 in.
18-24 Months28-30 lbs.32-34 in.
2T29-32 lbs.34-36 in.

Do Baby Clothes Run Small? 

Baby clothes vary from brand to brand; they can run longer, shorter, wider, or thinner. The clothing brand I found to be most accurate for my girls was Carter’s brand.

Gerber runs wider, and Old Navy clothes shrink like crazy. I always had to buy those in the next size up. When in doubt, buy the next size up. 

How Do You Know What Size Baby Clothes To Buy? 

You can use the baby size chart as a general guide; just remember not all brand sizes are the same. You can also do a quick search, and you should be able to find a chart for specific clothing brands to get an even closer estimate. 

Aside from the size charts, you can also estimate it. If your baby is getting a little big for a size, go the next size up, and if your baby just got into that size, you should be safe to continue buying clothes in that same size. 

How Much Weight Do Twins Gain Per Week After Birth? 

A singleton (1, single) baby gains about 5-7 ounces weekly. Since twins are born smaller than singletons, they have a growth difference after birth. 

According to the National Library of Medicine, after birth, twins grow faster but do not need the same size in height and weight as a singleton. However, after 2.5 years, they are generally the same size as a singleton. 

Do Twins Grow at the Same Rate After Birth? 

Twins are not going to be the exact same size. Generally, one will be a little smaller and the other a little bigger. However, they should ideally be growing at the same rate after birth, but that does depend on their health and how much they are eating as well. 

Related Questions:

Should You Buy Baby Clothes a Size Bigger? 

You should definitely have a stock of bigger-sized baby clothes. This makes your life so much easier when they grow from one size to the next so rapidly. 

As they get older and their growth rate slows down, you can slow down on how much you need in the next sizes up, but until they hit about 24 mo.-2T, I would definitely make sure you have enough clothes in each size to last about a week. 

As a new mom, you are pretty busy and won’t always have time to go shopping for a new wardrobe for your kiddos.

Is 0-3 Months the Same as Newborn? 

Simply put, no, it is not. 0-3 months is a larger size than newborn, as newborn ranges up to 5-8 pounds and 0-3 months ranges up to about 8-12 pounds.


I hope this gave you some insight on where to start with buying clothes for your babies. Enjoy preparing for your little ones, and best wishes on your own journey to motherhood.