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Best Kids Base Layers

Best Kids Base Layer

I’ll be the first to admit that I was late to jump on the baselayers for kids bandwagon. I’ve always loved and worn them as an adult, but I did not appreciate until very recently how much they truly make a difference in keeping kids warm from the inside out.

It’s easy to forget about or neglect this thin layer when thinking about winter gear for kids. Keeping kids warm for winter already requires a lot of gear (warm boots, mittens, snow pants, jackets, fleece, wool socks etc.).

I’ve always prioritized the gear on the outside but with time I’ve discovered that one of the best secrets for truly keeping kids warm is the layer on the inside.

I am now the biggest baselayer for kids convert, and I’m baffled on why it has taken me so long to invest in quality baselayers for my kids.

Sloomb Raven baselayer

If you’ve also been on the fence on whether quality baselayers are worth the investment then this post is for you. Below is a list of favorite baselayers for kids of all ages with input from the entire Mountain Mama Team.

It turns out we have lots of favorite brands for baselayers for different ages and stages. Thankfully, there are lots of great options out there.

Thinking about your budget and the needs and preferences of your child can help you make the best choice for your child.

As an Amazon Associate and member of other affiliate programs, we earn from qualifying purchases.

Discount codes on Kid Base Layers

  • Iksplor: Use code MTNMAMA20 to save 20%
  • Reima: Use code MTNMAMA to save 20%
  • Shred Dog: Use code MTNMAMA25 to save 25%; Use code MTNMAMA35 to save 35% on orders over $400
Boy wearing Sloomb Raven baselayer

Why Base layers Are So Important

What is a base layer?

A baselayer is the layer worn closest to your skin. Most baselayers tend to be on the thinner side but they come in variable thicknesses.

A good baselayer should be able to keep you warm and cozy while also wicking away moisture.

Since the main purpose of a baselayer is to move moisture away from the skin, the best baselayers will have good wicking properties.

Goal of base layers

Since this is the layer worn closest to the skin there are several important factors to consider when thinking about what kind of baselayer will work best for your kid.

Baselayer materials and how they feel

First, it’s important to consider what material will work best for your child. Knowing your childs’ sensory needs and what kind of fabrics they do/don’t like can help you make a more informed choice on what brand will be a good fit.

Consider how much your kids sweat

Another thing to consider is how much your child tends to perspire. Tweens and teens who are more prone to sweat might prioritize a material with good odor wicking capabilities while this might be of little importance for those with young babies.

Consider how warm or cold your kids run

Finally, it’s a good idea to know your childs’ preferred temperature. One of my girls is always hot. Getting her to wear a coat outside in the winter is like pulling teeth.

On the flip side I have another child that is always complaining of being cold. Her teachers at school tell me every year that she wears her winter coat in the classroom all day long.

I often wish I could pass off the heat from my hot child to warm up my freezing child. Sadly, this cannot be done but it has helped me recognize the importance of picking out baselayers based on my children’s natural preferences.

My child that runs hot prefers a thin, synthetic or merino wool layer and my child that’s always cold loves a thicker merino wool layer or doubling up her baselayer with a mid layer over top.

How base layers should fit

To best take advantage of the warmth that baselayers can provide the fit should be a snug, close to body fit. Many call baselayers a ‘second skin’ and this is how I like to think about them. The baselayer doesn’t need to be constrictive and some kids may like a more relaxed fit. However, for optimal moisture wicking, the ideal fit is for them to be snug like an additional layer of skin.

When to wear base layers

Baselayers are not only for winter wear under ski/snow gear (although this is a great use for them). The great thing about baselayers is that they can be used for recreational activities all year long.

Icebreaker baselayer worn while biking

They make great pajamas for camping in the summer and they are a great layer for under rain and snow jackets. Merino wool stays warm even when damp and synthetic fabrics tend to dry quickly.

Both have different strengths in wet environments.

We find baselayers are also essential to take hiking or backpacking when the temperature tends to fluctuate more.

Wool or Synthetic Base Layers?

Most base layers come in two main fabrics: merino wool or synthetic and both have advantages and disadvantages. The type that is best for your family will depend on your needs, activities, and budget. Merino and synthetics can both be worn year round (yes, wool in the summer too!).

merino wool vs synthetic baselayer infographic

Merino Wool Baselayers:

Merino wool comes from a special type of sheep called a Merino sheep. These sheep have very fine, soft wool fibers that contain lanolin, a natural antibacterial agent. Favorite features of Merino wool baselayers are that they are warm when wet, are odor resistant, sustainable, and soft.

wearing Sloomb Raven baselayer on log

Merino wool is great at temperature regulation and will help keep you warm on colder days and cooler on warmer days. Merino doesn’t dry fast if it is not in a dry environment, however, it will still keep you warm and won’t make you feel clammy even when wet.

Downside to Merino is that it is delicate and care must be taken to not damage the delicate fibers. Items can get snagged on Velcro, tree branches, hangnails, and gear. However, it is often repairable with a little needle and thread.

I learned the lesson about Merino’s delicacy the hard way when the first time my daughter was wearing her merino baselayers she got a hole in the knee. Thankfully little holes are easy to repair but it made me appreciate how delicate the fabric can be. That said, many families use them on a daily basis AND wash and dry them and they last for multiple kids.

smart wool set
Jami’s daughter wearing merino wool from Smartwool

Merino is best for layering in the cold or for multi-day use when you don’t want to pack a lot of baselayers.

Examples: Smartwool, Ik’splor, Ellas Wool, Sloomb

Synthetic Baselayers

Synthetic baselayers are most often made of polyester, nylon, spandex, etc. They come in a wide range of styles, price points, and technologies, like adding silver to aid in antimicrobial properties.

Although synthetic baselayers dry fast when wet, they do not keep you as warm when they are wet and can often leave you feeling clammy if the material doesn’t have airflow to dry.

Synthetics are best for warmer temps, more aerobic activities, or if there is prolonged wetness (from environment or sweat). They’re also great for kids who have wool allergies.

Examples: Patagonia Capliene, REI, Shred Dog

Mixed Blend

Some companies have started mixing Merino wool and synthetic materials to try and capture the best of both worlds. They start with using primarily Merino wool for its odor resistance, breathability, and softness. Then add in some polyester to aid in faster wicking and making the product lighter weight.

These mixed blend items are great for higher intensity aerobic activities when you still want the best wool properties but want to stay drier.

Examples: Helly Hensen, Reima, Isbjorn

So What is Best?

Both Merino wool and synthetic baselayers stand out in certain areas and most of us have a mix of synthetic and Merino baselayers. It all comes down to personal preference and what kind of material is best for the activities you are doing.

Best Baselayers for Babies

Below is a list of our favorite baselayers for the littlest ones in your family.

Ellas Wool

Ellas wool is a company based out of Brooklyn, NY. Becca’s Norwegian roots were her inspiration to start the company when she couldn’t stand to see empty playgrounds in the winter after moving to New York.

baby girl wearing Ella's wool
Jami’s daughter wearing Ella’s wool

What we love about Ellas wool is that the merino wool is super soft and warm. They claim to be buttery soft, and I can vouch for how warm and cozy they are.

The baby baselayers are footed which keeps feet warm too. They come in moss green, gray, navy blue and pink.

The Ella’s Wool baselayers are so soft and snuggly. I didn’t like that the baby set only had footed bottoms, so I purchased a onesie and un-footed pant separately. This was great because I was able to use them longer and didn’t worry about extra pressure on the bottom of the feet when in a carrier. Currently this doesn’t appear to be an option on the site but may be as stock comes back.

TMM Team Member Jami

You can read our full review on Ella’s Wool TUBES as well. These are a great heavier weighted wool baselayer for kids 9 months-7years.

>>> Use code: “MTNMAMA21” for 10% off Ellas Wool<<<

Jami’s daughter wearing Ik’splor top with Ella’s wool tubes and Smartwool socks.

Quick Stats: Ella’s Wool Baby Baselayers

  • Price: $59 for onesie and footed pant set
  • Fabric: 100% Merino wool (21.5 micron)
  • Size: 3-18 months


Iksplor’s tagline is that better days start with a better base. This company based out of Jackson, WY has two great merino wool options for babies.

They have a baby Iksplorer set as well as a baby adventure onesie.

The Ik’splorer set and adventure oneside both have handmitts for sun and snow and are made of 100% merino wool. Unlike Ella’s wool, the feet are open on the Ik’splorer set and the baby adventure onesie.

The main difference between the two options is that the adventure onesie is made with a mid-weight wool while the Ik’splor set is thinner. The onesie might be the preferred option if you are in frigid temps or want a looser fitting mid-layer.

If your baby is in between sizes then I would order the size larger.

Stephanie’s baby wearing Ik’splor set

The 3-6 month Ik’splorer set fits quite snug on my average sized 3mo daughter and she will outgrow it sooner than I was hoping. I wish I ordered the 6-12 month option instead.

TMM Team Member Stephanie

>>> Use code: “MTNMAMA20” for 20% off Iksplor<<<

Quick Stats: Iksplor set and adventure onesie

  • Price: $89 (both)
  • Fabric: 100% Merino wool (18.9 micron)
  • Size: 0-24 months for the set & preemie-24 months for the onesie

Patagonia Infant Capilene

Patagonia Infant Capilene baselayers are made with 100% recycled polyester. The onesie has fold over cuffs and reinforced elbows. The bottoms also have reinforced knees.

The sizing was generous a few years back, but the product has changed a little. Check out current customer reviews for sizing suggestions.

We’ve had such luck with Patagonia, they last forever and I think they are my favorite.

TMM Team Member Jen

Quick Stats: Patagonia Capilene

Wee Woolies

Wee woolies is a company based out of Vancouver, BC that prides themselves on being a completely natural product through and through.

They’re made with 100% New Zealand merino and the baby baselayer set comes in lots of fun two-toned colors.

Our Wee Woolies have made it through 3 kids and still look great.

TMM Team Member Anna

Quick Stats: Wee Woolies

  • Price: $65
  • Fabric: 100% Merino wool (18.9 micron)
  • Size: 0-18 months

Best Baselayers for Toddlers and Kids

Toddlers and kids also need warm, cozy baselayers. Some of our favorite brands for this age group include Helly Hansen, Ik’splor, Icebreaker, Smartwool, Sloomb, Reima and Isbjorn.

Helly Hansen

Helly Hansen has a mixed blend base layer that is comfy to wear. Helly Hansen uses a 2 layer construction to make these baselayers and they’re designed to wick away moisture for super active kids. They have reinforced elbows and knees which is great for active kids.

Sleeping in Helly Hansen thermals
Anna’s daughter wearing Helly Hansen

HH runs on Euro sizing, so measure your kiddo before ordering to ensure a proper fit, but sizing starts at about a 12month equivilent size.

When I was looking for Kylie’s first real baselayer, we came across Helly Hansen and was pleased that they had nice base layers for tiny humans and a sale sealed the deal. My oldest wore hers for 2 winters and now my youngest is in them (size 92/2 -wears 2T/3T clothing). Aside from a few stains, they have held up great!

TMM Team Member Jami
Jami's daughter wearing Helly Hansen
Jami’s daughter wearing Helly Hansen

Quick Stats: Helly Hansen Lifa Merino

  • Price: $75.00
  • Fabric: 57% Merino Wool, 43% Polypropylene
  • Size: 86/1-134/9


While Icebreaker baselayers are one of the priciest merino wool brands out there, their thermals are called the Oasis for a reason. These baselayers are designed to move with the body and contour to every body movement.

The merino wool jersey fabric is designed to be comfortable and soft.

My daughter ended up with a pair of Icebreaker baselayer bottoms in a bag of hand-me-downs and those have held up incredibly well and are really soft too. She wears them as regular leggings at her nature preschool and we’ve had them for two years (and I think they went through two kids before us) and they still look awesome.

TMM Team Member Cait
wearing icebreaker baselayer in sand
Cait’s daughter wearing Icebreaker bottoms

My daughter loves icebreaker shirts…Super warm but not as soft as HH or Smartwool.

TMM Team Member Jen

Quick Stats: Icebreaker

  • Price: $55/top & $55/bottom
  • Fabric: 100% merino mid weight jersey
  • Size: 2-14


Iksplor not only has a great baby set but they’re baselayers for toddlers and kids are also loved by the team.

Their kid set is designed to fit long in the torso, back and sleeves to make sure kids are well protected from the elements.

Boy wearing Ik'splor outside
Stephanie’s 2yo wearing Ik’splor

This is my favorite part about the Iksplor design. I ordered one size up for all my kids and anticipate my kids being able to wear them for 2 seasons with how long the fit is.

The wool is neither scratchy nor itchy and the fabric is thin while still holding up well after multiple uses.

My daughter loves the Ik’splor set we bought…they are super soft and the right level of thickness, and she’s a huge fan of the thumbholes (who isn’t?).

TMM Team Member Cait
Testing out Ik'splor thumbholes
Cait’s daughter showing off Ik’splor thumbholes

>>> Use code: “MTNMAMA20” for 20% off Iksplor<<<

Quick Stats Iksplor Kids Baselayers:

  • Price: $109
  • Fabric: 100% Merino wool
  • Size: 2-12 years


Isbjorn is a Swedish brand that also makes a quality mixed baselayer with merino wool and bamboo.

The goal behind this particular line was to create a baselayer that was relatively thin, stretchy and soft while also being durable.

My son loves the husky baselayer because they fit more loose and he has sensory issues.

TMM Team Member Anna

They sells their husky baselayers as two separate pieces.

Quick Stats: Isbjorn

  • Price: $50/top & $50/bottom
  • Fabric: 48% merino wool, 43% viscose (bamboo), 9% polyamide
  • Size: 12 month – 14 years


Reima seems to be in a league of their own as far as kids’ gear is concerned and their baselayers are no exception. This Finnish brand is constantly impressing our team with all their well made gear.

Many team members love these base layers due to their thick softness and warmth.

My boys love their Reima baselayers but often the don’t wear them because they get too warm. Go figure!

TMM Team Member Rita

Team members also mentioned that Reima baselayers are more affordable than other brands and love having an option that’s high quality but doesn’t break the bank.

Reima has several different styles and baselayer fabrics. The variety of different options is almost overwhelming but I love that there is are so many different options at different price points.

Silly kids ready for adventure in Reima base layers
Silly kids ready for adventure in Reima base layers

I like the Reima layers, the price is good and they have a merino tencel blend that is really soft and silky.

TMM Team Member Kristin

Reima has really great soft and thick polypro baselayers.

TMM Founder Amelia

Team members reported liking both the polypro Reima baselayer (called the Lani) and the merino tencel blend (called the Kinsei).

I plan to order the merino wool blend that’s mixed with bamboo (called the Taitoa) the next time I’m purchasing baselayers for my kids as my kids love bamboo fabrics. Amelia’s kids use them and say they are the softest they’ve ever used and their favorite Reima base layers.

Keep in mind that all Reima products run about a size larger so avoid sizing up.

>>> Use code: “MTNMAMA” for 20% off Reima<<<

Quick Stats: Reima Thermolite

  • Price: $59.95
  • Fabric: 43% polyester THERMOLITE®, 53% polyester, 4% sorona
  • Size: 12 month-14 years

Quick Stats: Reima Kinsei

  • Price: $64.95
  • Fabric: 72% wool, 28% lyocell
  • Size: 12 month-14 years

Quick Stats: Reima Taitoa

  • Price: $74.95
  • Fabric: 48% merino wool, 43% viscose (bamboo), 9% polyamide
  • Size: 12 month – 14 years


Another great option for kids is the Sloomb Raven line. It is a thicker baselayer made of 100% merino wool that provides additional warmth for those in extra cold climates or for kids that are always complaining that they are cold.

Wearing Sloomb Raven baselayers on water
TMM Kristin’s kids wearing Sloomb Raven

They have a looser fit for kids who struggle with tight fitting clothes..

One downside of the Raven line is that products are final sale, however it is nice that the tops and bottoms come as separates. The Raven line comes in many beautiful earth tone colors as well and a wide range of sizes beyond the ones sized just for kids.

We have lived in Sloomb layers for years. They’re really comfortable and wash up great.

TMM Team Member Kristin

Quick Stats for Sloomb Raven:

  • Price: $45/top & $45/bottom
  • Fabric: 100% Merino wool
  • Size: 2-10 years

Smartwool base layers for kids

Jami's daughter wearing Smartwool Merino baselayers
Jami’s daughter wearing Smartwool baselayers

Smartwool’s baselayers are made with 100% Merino wool. They are thicker than Iksplor as they come in a 250 weight, but they are still soft. We love that you can get coordinating patterns with hats, neck gaiters, adult baselayers, and headbands.

We have been using Smartwool Merino 250 baselayers with my oldest daughter for 3 years now. She was able to get two years out of one set before sizing up with only a few minor repairable holes. They are still in great shape for little sister. They are warm and soft!

TMM Team Member Jami

Tops and bottoms are sold separately so you can mix and match patterns too or get two tops and one bottom if the shirts tend to get dirtier.

Wildhaven Wools

Wildhaven wools are 100% wool baselayers made in small batches in Haines, Alaska. They have adorable appliques (mountains and flowers) and have thinner and thicker options in addition to “grow with me” cuffs on some styles.

Two kids indoors hugging in their wool layers, a white blonde boy in black, green, and blue; and a white blonde girl in red, pink, and green.

All Wildhaven wools are sold in sets with a top and bottom. They have crew cuts and also the option for a beautiful hoodie style (plus kangaroo pocket!) with the Signature Merino sets, that would be a dream woolie outfit right there (sorry adults, they only come up to size 9Y).

The Signature Merino sets (pictured in red and pink with green cuffs) have “grow with me” cuffs on the arms, legs, and waist. The waist is not made of wool, and it holds up fantastic and stayed up without stretching. The Minimalist Merino Sets (pictured in black and blue with green trim) have merino on the waist, and it did eventually stretch out as wool will do, but we were impressed that it held up for half a dozen wears before it started to sag.

The Signature sets are thicker (200gsm) than the Minimalist (150gsm) and offer more options for customization. The knee patches on the newer sets have moved up a bit, they’re a bit low for my daughter. I’d love if they were even bigger, but it’s really great that they’re adding them and I would love to see even bigger and thicker patches as options in the future for kids who play really rough.

Quick Stats: Signature Merino sets

  • Price: $107 – $215 (depending on size, applique selection, and selection of hood)
  • Fabric: 100% merino wool on shirt and pants, 95% organic cotton, 5% spandex waistband
  • Size: 6 months – 9+ years

Quick Stats: Minimalist Merino sets

  • Price: $79 – $119 (depending on size)
  • Fabric: 100% merino wool on shirt and pants; 94% merino wool, 6% spandex waistband and neckband
  • Size: 12 months – 11 years
Two kids in colorful wool layers and helmets playing in the snow

Best Baselayers for Tweens/Teens

Helly Hansen

Helly Hansen has a mixed blend base layer set that is also super popular among the older kids of our team members.

I grabbed Helly Hansen kids wool base layers on sale and they are the ones my daughter reaches for first.

TMM Team Member Anna

I found Helly Hansen half off on Amazon Warehouse. These are wool and soft. I hear they wear out, but we’re two seasons in and no holes.

TMM Team Member Jen

Helly Hansen uses a 2 layer construction to make these baselayers and they’re designed to wick away moisture for super active kids.

Quick Stats: Helly Hansen Lifa Merino

  • Price: $75.00 for Kids set, $100 for Junior set
  • Fabric: 57% Merino Wool, 43% Polypropylene
  • Size: Kids 86/1-134/9, Juniors 128/8-176/16

REI base layers for kids

The final brand loved by tweens and teens among our group are the REI Co-op Long Underwear Tops/Bottoms.

Teens tend to like that they are not itchy and feel like they’re a great, comfortable product at a great price point.

The teens favorite baselayers are cheap ones I got from the REI brand on clearance.

TMM Team Member Rita

I grabbed a pair of REI brand kid baselayer pants for myself on clearance and I like the fit and feel of those better than my more expensive Smartwool bottoms.

TMM Team Member Cait

Quick Stats: REI Co-op Long Underwear Tops/Bottoms

  • Price: $29.95/top & $29.95/bottom
  • Fabric: 89% polyester/ 11% spandex
  • Size: XXS (size 4/5) to XL (18)

Shred Dog

Of all the synthetic blend options available Shred Dog’s foundation kids baselayer seem to be the most loved by the team for the older kids. Their foundation baselayer top and bottom come in sizes small to extra large.

Shred Dog is a company that cuts out the middle man and sells direct to you. Their model is designed to get parents quality gear while avoiding the retail markup.

Shred Dog love that their base layers are moisture wicking, quick drying and have 4-way stretch and hideaway thumb holes. Shred Dog base layers are a little thicker material that can also work as a mid layer. Amelia’s kids prefer them layered with Iksplor for the best base layers for skiing.

Some things to keep in mind are that the large and extra large pants run quite wide in the waist.

A bonus of the more relaxed fit and style is that you can layer them over top of a thin baselayer on super cold days.

Amelia’s girls wear them as their daily leggings too.

Shred Dog base layers are great for camping, mid layers and for kids sized 4-16. Biking in Shred Dog layers
Shred Dog base layers are great for camping, mid layers and for kids sized 4-16

>>> Use code: “MTNMAMA25” for 25% off Shred Dog Gear<<<

Quick Stats: Shred Dog

  • Price: $36.00/top & $30.00/bottoms
  • Fabric: 87% Polyester, 13% Spandex
  • Size: (Sm-XL)

Others Base Layers to Consider

As I mentioned previously the Mountain Mama team compiled a large list of baselayer favorites. It was hard to pick which ones really stood out as the cream of the crop.

Others that received honorable mentions were Burton. TMM Team Member Jen reports that they are easy to find cheap and they are just as durable as Patagonia. TMM Team Member Sarah loves them too. Check out more about them in our Burton round-up here.

The best budget option seems to be 32 Degrees sold seasonally at Costco and Amazon. I was able to snag synthetic base layers for multiple kids for less than $15/pair.

Mountain Warehouse – BUDGET PICK

These base layers are a lighter weight Merino wool blend, perfect for warmer weather or aerobic activities. Don’t size up, order your current clothing size.

These base layers are a bit thinner than most others we have tried and worry about the longevity, but for the price it was worth a shot! I grabbed some around black Friday for half off.

TMM Team Member Jami

Quick Stats: Mountain Warehouse

  • Price: $24.99/top & $24.99/bottoms – but they are ALWAYS running a sale.
  • Fabric: 70% Merino Wool, 30% Polyester
  • Size: 2T to Youth 13-14

Caring for your Base Layers

Keeping your baselayers in tip-top shape will allow them to perform better, last longer, and give you some good resale value on those expensive merino wool pieces.

Jami's daughter wearing Ik'splor
Iksplor base layers – use code MTNMAMA20 for 20% off

Merino Care

Due to the natural odor resistant properties of merino, your merino pieces can go quite a while without a washing. They do NOT need a wash after every wear. TMM Team Member Jami only does a wool clothing load every 3-4 weeks, depending on use (and that’s even on her sweaty running Merino!).

Most Merino pieces listed here can be machine washed on cold/delicate. A wool wash is recommend by most brands to keep the Merino in tip-top shape. Check out Nikwax Wool Wash to keep your wool fresh. Most Merino pieces listed (except Ella’s Wool) can also be tumble dried on low.

About once a month, I gather all the Merino I can find in the house and wash with Nikwax Wool Wash. It comes out smelling fresh and its nice and soft after drying.

TMM Team Member Jami

Synthetics Care

Synthetic base layers tend to be a little more durable in the wash. They will require more frequent washing than your Merino layers, likely after every sweaty use, might get 2 wears out of an item if not sweaty. Nixwax Basewash is a great way to keep those base layers clean. A lot of detergents can leave residue behind that hang on to odors. Base wash helps clean and deodorize synthetic base layers.

Most synthetics can be tumble dried on low, but air drying is best for some pieces.


Baselayers will be a game changer for your kids if they aren’t already using them.

If they are using them and don’t love them or avoid wearing them then it might be worth trying another brand to get a fit, fabric, or style that works better.

As a team we speak from experience that warmth truly comes from the inside out and warm kids will stay and play longer outside with less complaining.

Any great baselayers we missed? Please share, we would love to try out your favorite and add to our review!

Cait's daughter wearing Icebreaker

Related Articles:

Best Baselayers for Kids

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