What Size Clothes for Newborn Twins? Advice From Twin Mom

Every mother wants to make sure they have enough clothes for their newborns. But figuring out the right sizes can be tough, especially for those who are having twins.

What size clothes do you buy for newborn twins? The size your newborn twins will need depends on factors you won’t know before birth. How early your twins are born, growth rates, and what type of twins they are will all play a role in their size. To be prepared, have a few pairs of preemie clothes and at least five outfits each in newborn size.

There are ways to plan to make sure you have clothes that will fit your babies. You just need to know what you can about baby clothes and how they work. Let’s dive in.

Clothing Sizes for Newborn Twins

With twins, due dates are unpredictable and subject to change quickly. That’s why buying clothes for newborn twins can be such a challenge. It’s very unlikely that your pregnancy will go past 37-38 weeks at the most.

Identical twins face a riskier time in the womb and may have to be taken earlier than fraternal twins. This can lead to them being even smaller when born. Your children’s rate of growth after birth will also impact what clothes they need.

How Do Baby Clothes Sizes Work?

Baby clothes sizes often come in a range based on months of age. For example, 0-3 months means this size will be a bit oversized on a one-month-old but should fit most three-month-old babies just fine.

It’s also important to know that different brands fit differently, even if they are the same size. A onesie sized 6-9 months from one store may not fit the same as a different brand that is sized the same.

Do Twins Need Preemie Clothes?

Though it may be tempting to stock up on tiny preemie clothes, many twins won’t need them. My twins never wore preemie clothes because they were born at 37 weeks. Though small, they still fit in newborn sizes just fine.

Even if your babies are premature, they won’t have a need for preemie clothes in the NICU. Your child will wear whatever the hospital deems appropriate so they can be monitored properly.

Plus, the goal of the NICU stay will be to put weight on your babies and help them grow. They will grow out of preemie clothes quickly.

If you have preemies who are able to go home fairly soon after birth, you may need a few pairs of preemie sizes.

Preemie Clothes Weight

Preemie clothes tend to work for babies who are between 3 and 6 pounds. When it comes to height, a baby between 16-18 inches will fit in this size. 

It’s important to remember that your twins will likely grow quickly if all goes well, so you shouldn’t need a lot of preemie clothes.

Newborn Clothes Weight

Some babies skip the newborn clothes completely since this size is only for babies who are between 7 and 9 pounds.

However, since twins are usually born early and weigh less, you may need several pairs of newborn clothes. They have a pretty wide height range of between 17 and 21.5 inches.

My twins were born weighing 5 1/2 pounds a piece, so newborn sizes fit them well for the first month. They were slightly too big in the beginning, but they were perfect after the first couple of weeks.

Newborn fraternal twins sleeping side by side while wearing onesies.

0-3 Month Clothes Weight

Clothes sized 0-3 months will likely fit your babies for a while if they are twins. These fit babies who are between 8 and 12 pounds and 19-24 inches long.

Some babies skip the newborn size and move immediately to 0-3 months, but this isn’t always the case with twins. You may need a few newborn options until your babies are big enough not to be swallowed by this size.

How Many 0-3 Clothes Do I Need?

A good estimate for clothes labeled 0-3 months is around 10 onesies a piece. This keeps you from having to constantly wash clothes when there are diaper accidents.

Baby Clothes Sizing 

Baby ClothesWeightHeight
Micro1-3 poundsUnder 16 inches
Preemie3-6 pounds16-18 inches
Newborn7-9 pounds17-21.5 inches
0-3 Months8-12 pounds19-24 inches
3 Months9-12.5 pounds23-26 inches
6 Months12.5-17 pounds24-27 inches
9 Months16-20 pounds26-28 inches
12 Months20-24 pounds28-31 inches
18 Months224-28 pounds30-32 inches

How Long Twins May Need Newborn Clothes

Your twins will likely need newborn clothes for at least the first month. However, every situation is different.

When To Move Up a Size in Baby Clothes

You will know when it’s time to go up a size in baby clothes. The cute little onesies that previously went on easily will suddenly have a hard time zipping, snapping, or buttoning all the way.

If your child can’t fully straighten his legs while in a onesie or the clothing pinches or leaves red marks, it’s too small. 

Clothes for Twin Babies

There are some essentials you will want to have around after the birth of your twins.

  • Onesies
  • Pants
  • Swaddlers
  • Baby hats

Other items are fun but not always necessary.

  • Baby socks
  • Baby shoes
  • Pajamas
  • Coats/jackets/sweaters

Do Twins Develop Slower Than Singletons?

Twins may develop slower than singletons post birth, but that’s not always the case.

Twins who are premature will have an adjusted age, meaning they may look like they are developing slower than other kids their actual age, but they are on track for when they were born. 

Related Questions: 

Is 0-3 Months the Same as 3 Months?

Most babies can wear clothes marked 0-3 months and 3 months interchangeably. Three-month clothes may be slightly larger than the 0-3 size.

What Size Clothes Do Babies Wear the Longest?

As babies age, they tend to wear clothes longer. That means the larger sizes won’t be grown out of as quickly as the sizes they wear for the first nine months.

Final Thoughts

Enjoy shopping for cute clothes, whatever size your babies need! Just keep in mind that they will size out rapidly, so don’t overdo it in any one size.