Smartwool Men's Classic Thermal Merino Wool Base Layer Crew (Slim Fit)

4.7 out of 5 stars 530 ratings
Price: $95.99 $114.95 Free Returns on some sizes and colors

Black
Size Chart
US Regular
Brand SizeChest (in)Waist (in)Hip (in)Length (in)
XS33 - 3526 - 2833 - 3530 - 31
S36 - 3829 - 3136 - 3831 - 32
M39 - 4132 - 3439 - 4132 - 33
L42 - 4435 - 3742 - 4433 - 34
XL45 - 4838 - 4045 - 4834 - 35
2XL49 - 5141 - 4449 - 5135 - 36

Product details

Fabric type
100% Merino Wool
Care instructions
Cool iron, Do Not Bleach, Gentle cycle
Origin
Made in the USA
Closure type
Pull On

About this item

  • COLD WEATHER BASE LAYER. Keep your ski or hiking boots free of bulk and friction with our 3/4 Bottom. Merino wool provides ultimate comfort, while a newly redesigned base layer pants fit helps reduce sag and excess fabric—perfect for layering.
  • SLIM FIT. Designed to meet the demands of outdoor adventuring, these slim fit bottoms show off a slimming silhouette while offering unrestricted movement through the legs. Inseam: 21.5"
  • CLASSIC THERMAL MERINO. Ideal for cold-weather activities where warmth and breathability are crucial, this midweight fabric used a Merino wool construction that helps move moisture away from skin to keep you warm and dry.
  • FUNCTIONAL FEATURES. Go far, feel good with thoughtful tech to keep you trekking comfortably — interlock knitting enhances breathability, thermoregulation and moisture-wicking while flatlock seams minimize chafing for greater comfort.
  • GO FAR. FEEL GOOD. From wool socks to base layers for men, women and kids, we aim to provide the highest quality apparel for your outdoor adventures with a commitment to environmental sustainability, racial equity and inclusivity.
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Smartwool Men's Classic Thermal Merino Wool Base Layer Crew (Slim Fit)
This item: Smartwool Men's Classic Thermal Merino Wool Base Layer Crew (Slim Fit)
$114.74
Get it as soon as Tuesday, Jul 1
Only 2 left in stock - order soon.
Sold by Amazin Group and ships from Amazon Fulfillment.
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Smartwool Men's Classic Thermal Merino Base Layer Bottom
$115.00
Get it as soon as Tuesday, Jul 1
Only 2 left in stock - order soon.
Sold by MetroShoe Warehouse and ships from Amazon Fulfillment.
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  2. Sustainability features

    This product has sustainability features recognized by trusted certifications.
    Safer chemicals
    Made with chemicals safer for human health and the environment.
    As certified by
    OEKO-TEX STANDARD 100

    OEKO-TEX STANDARD 100

    OEKO-TEX® STANDARD 100 certified products require every component of a textiles production including all thread, buttons, and trims to be tested against a list of more than 1,000 regulated and unregulated chemicals which may be harmful to human health and the enviornment. The assessment process is globally standardized, independently conducted, and updated at least once per year based on new scientific information or regulatory requirements.

    Certification Number

    SHGO 069338

    Climate Pledge Friendly

    Discover more products with sustainability features.Learn more
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From the brand

Product Description

Smartwool high performance merino wool apparel for men, women and kids.
The best gear for nature. High quality performance outdoor apparel made out of marino wool.
Merino wool is a sustainable, natural fiber that is thinner and softer than regular wool.
Merino wool, is super soft, resists odor, keeps you dry, and is renewable.
Smartwool Mens Intraknit Thermal Merino Wool Base Layer
Hike Classic Edition Light Cushion Crew Socks
Womens Classic Thermal Merino Base Layer 1/4 Zip
Womens Classic Thermal Merino Base Layer Bottom
Hike Classic Edition Light Cushion Crew Socks
Womens Run Zero Cushion Low Ankle Socks
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Customer Reviews
4.6 out of 5 stars 16
4.6 out of 5 stars 857
4.0 out of 5 stars 1
4.5 out of 5 stars 586
4.6 out of 5 stars 808
4.7 out of 5 stars 590
Price $79.40 — no data — no data $97.02 — no data — no data
Multiple Color Options ✓ ✓ ✓ ✓ ✓ ✓
Smartwool is creating a climate-positive way of doing business through sustainable farming.

Product details

  • Package Dimensions ‏ : ‎ 11.02 x 9.92 x 1.46 inches; 9.59 ounces
  • Item model number ‏ : ‎ Smartwool
  • Department ‏ : ‎ mens
  • Date First Available ‏ : ‎ September 19, 2020
  • Manufacturer ‏ : ‎ Smartwool
  • ASIN ‏ : ‎ B08BDQK37G
  • Customer Reviews:
    4.7 out of 5 stars 530 ratings

Top Brand: Smartwool

Highly Rated
100K+ customers rate items from this brand highly
Trending
100K+ orders for this brand in past 3 months
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Customer reviews

4.7 out of 5 stars
530 global ratings

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Customers say

Customers find the thermal shirt keeps them warm without being itchy, and appreciate its breathability for indoor wear. The fit is particularly suitable for men with long arms, and customers like its durability and style, with one noting it's the best in the merino game. Customers describe the shirt as lightweight and soft, with one mentioning it's heavy enough to wear over a tee. While some customers say it's worth every penny, others find it pretty damn expensive.

Select to learn more

WarmthComfortFitDurabilityLightweightSturdinessStyleValue for money
27 customers mention "Warmth"24 positive3 negative

Customers find the thermal shirt keeps them warm and is breathable enough to wear all day indoors. One customer mentions it was a lifesaver during a snowmobiling trip to Yellowstone, while another notes it made their trip to Iceland more enjoyable.

"This top kept me warm in 50 degree temperatures in a tent while camping." Read more

"...I was initially skeptical due to the price, but this was a great winter essential that also wicked my sweat in warmer temps." Read more

"Lifesaver during my snowmobiling trip to Yellowstone!..." Read more

"This baselayer top is awesome, is very warm, and comfortable to wear all day. It's long so it easily tucks in and stays that way...." Read more

19 customers mention "Comfort"19 positive0 negative

Customers find the shirt comfortable and soft, with one customer noting it's warm without being itchy.

"Looks good, feels good, wears well. Nice color. Can be worn several times between laundering. I own four shirts in different colors...." Read more

"...Very comfortable, comfortable, but don’t let lightweight fabric for you, it really does its job well! Cheers!" Read more

"...I expect it will give me years of good comfortable service, because using it as a hiking and climbing base layer next to my skin will subject it to..." Read more

"This baselayer top is awesome, is very warm, and comfortable to wear all day. It's long so it easily tucks in and stays that way...." Read more

18 customers mention "Fit"15 positive3 negative

Customers find the thermal shirt comfortable and well-fitting, with longer sleeves than expected, making it particularly suitable for men with long arms.

"...It’s his go to long sleeve shirt." Read more

"Lifesaver during my snowmobiling trip to Yellowstone! Very comfortable, comfortable, but don’t let lightweight fabric for you, it really does its..." Read more

"...Or, if you don't tuck it in, the long waist hugs your hips and keeps the wind from blowing up into your open coat...." Read more

"...The cut is fitted but not too tight, so it looks as good on a hike in the wilderness as in a smart-casual restaurant or bar...." Read more

11 customers mention "Durability"11 positive0 negative

Customers appreciate the shirt's durability, noting its well-made construction and high-quality merino wool material, with one customer mentioning it has lasted well over time.

"Looks good, feels good, wears well. Nice color. Can be worn several times between laundering. I own four shirts in different colors...." Read more

"...thin, unsealed, clear plastic sleeve it was shipped in, it held up admirably well...." Read more

"...So while this is expensive, it has lasted and is great quality...." Read more

"Love this company. The quality did not disappoint as always Made my trip to Iceland much more enjoyable knowing I could rely on the warmth." Read more

10 customers mention "Lightweight"10 positive0 negative

Customers appreciate the shirt's lightweight design, with one customer noting it's heavy enough to be worn over a tee.

"Light, but provides the right amount of cooling and warmth...." Read more

"...They're perfect for travel as they're light-weight and wrinkle-free...." Read more

"...Tried it on again, no shrinkage, same fit. It's 250 weight and doesn't feel thick or heavy. Very satisfied...." Read more

"I absolutely love my Smartwool sweater. It’s lightweight enough to wear under a shirt or heavy enough to be worn over a tee, preferably a..." Read more

6 customers mention "Sturdiness"6 positive0 negative

Customers find the shirt sturdy, with one mentioning it's the best in the merino game.

"Smartwool products are all really amazing. I love this base layer!" Read more

"...Smartwool is magical." Read more

"Smartwool one of the best in the merino game. You get what you pay for...." Read more

"...This is a great product." Read more

6 customers mention "Style"6 positive0 negative

Customers like the style of the shirt, noting its great look and nice color, with one customer describing it as an awesome cool weather shirt.

"Looks good, feels good, wears well. Nice color. Can be worn several times between laundering. I own four shirts in different colors...." Read more

"Very soft and comfortable, attractive print" Read more

"What a nice design. Very stylish. Fits slightly large. I am a wide framed medium. And still a tad loose. Looks good. Very soft. I will purchase more." Read more

"Great look and fit. Just the right amount of warmth while being light weight...." Read more

15 customers mention "Value for money"7 positive8 negative

Customers have mixed opinions about the shirt's value, with some finding it worth the price while others consider it expensive.

"...I think they are a bit overpriced." Read more

"...Definitely recommend. It's worth the cost. Also, the price on this in Oct 2021 was $20 cheaper than the 2nd one I bought in January...." Read more

"It is not cheap but you get what you pay for. My favorite base layer ever!!! I am 5'11 and 200 pounds. The XL fits me well...." Read more

"Smartwool a very intelligent buy!" Read more

Top reviews from the United States

  • Java developer
    5.0 out of 5 stars Warm and good for camping
    Reviewed in the United States on June 13, 2025
    Size: LargeColor: BlackVerified Purchase
    This top kept me warm in 50 degree temperatures in a tent while camping.
    Helpful
     Report
  • Sammie
    5.0 out of 5 stars Boyfriend loves it
    Reviewed in the United States on May 29, 2025
    Size: MediumColor: Charcoal HeatherVerified Purchase
    I bought this for my boyfriend and he absolutely loves it! It’s his go to long sleeve shirt.
    Helpful
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  • Ricky L
    5.0 out of 5 stars Worth every penny
    Reviewed in the United States on May 18, 2025
    Size: LargeColor: Charcoal HeatherVerified Purchase
    Light, but provides the right amount of cooling and warmth. I was initially skeptical due to the price, but this was a great winter essential that also wicked my sweat in warmer temps.
    Helpful
     Report
  • JBHerman
    5.0 out of 5 stars Smartwool quality
    Reviewed in the United States on March 3, 2025
    Size: LargeColor: Twilight Blue HeatherVerified Purchase
    Looks good, feels good, wears well. Nice color. Can be worn several times between laundering. I own four shirts in different colors. Most brands are only available in black.
    Helpful
     Report
  • racerx
    5.0 out of 5 stars Not itchy and easily can wear all day
    Reviewed in the United States on February 15, 2025
    Size: X-LargeColor: BlackVerified Purchase
    Switched from under armor to these. These run a little bigger and are about as thick as the 2.0. I wear 2xl in under armor and went with an 1xl on these. Fit great
    2 people found this helpful
    Helpful
     Report
  • hdm8090
    5.0 out of 5 stars Satisfied customer
    Reviewed in the United States on February 17, 2025
    Size: X-LargeColor: Nival Blue/Deep NavyVerified Purchase
    Lifesaver during my snowmobiling trip to Yellowstone! Very comfortable, comfortable, but don’t let lightweight fabric for you, it really does its job well!
    Cheers!
    Helpful
     Report
  • Dan
    5.0 out of 5 stars Proven Durability
    Reviewed in the United States on December 1, 2024
    Size: X-LargeColor: Charcoal HeatherVerified Purchase
    A very durable soft wool fabric! Despite the fact that this fine wool garment was delivered partially outside of the very thin, unsealed, clear plastic sleeve it was shipped in, it held up admirably well. I expect it will give me years of good comfortable service, because using it as a hiking and climbing base layer next to my skin will subject it to less wear and tear than it experienced during the shipping process.
    Helpful
     Report
  • Kenny
    5.0 out of 5 stars outstanding warth
    Reviewed in the United States on December 29, 2024
    Size: X-LargeColor: BlackVerified Purchase
    I am a veteran and these things are way better than what I was issued in Alaska (88-90) obviously cold weather clothing has made major improvements
    Helpful
     Report

Top reviews from other countries

Translate all reviews to English
  • 美味しいもの食べたい
    5.0 out of 5 stars とても快適です(暖かさはまぁまぁ)
    Reviewed in Japan on December 28, 2023
    Size: MediumColor: Charcoal HeatherVerified Purchase
    凄く温かいか? と言われると個人の感覚なので断言は難しいですが、まぁまぁ温かいと思います。
    感覚で言うと、着るレイヤーをひとつ減らせるかも? くらいの感覚です。
    これでも凄いですよね。
    比較的体にフィットする仕立てのお陰で隙間無くボディーラインに沿ってくれるため暖かさを維持してくれているようです。
    メリノウール 100% でなんだと思いますが、肌触りも優しく着ていて不快感もありませんし、汗を掻いても不快に感じませんね。
    山行とスキーでの使用を考えて購入し、山歩きで使用しましたが春秋のベースレイヤーとしてとてもお勧めです。
    Report
  • Tracy
    5.0 out of 5 stars Smartwool...fantastic quality as always!
    Reviewed in Canada on January 6, 2021
    Size: XX-LargeColor: BlackVerified Purchase
    Bought this for my husband, spends hours on end in a treestand in the fall and winter. We both love Smartwool products and as usual, this underlayer does not disappoint. Had previously worn a 150 underlayer and upgraded him to a 250!
    Report
  • Cliente de Amazon
    1.0 out of 5 stars El producto es usado
    Reviewed in Mexico on December 17, 2024
    Size: MediumColor: Charcoal HeatherVerified Purchase
    El producto llegó sin ninguna etiqueta, lleno de bolitas de uso como si hubiera sigo usado anteriormente. No lo recomiendo y menos para el precio.
    Report