Base layers are a bit weird. For one, you want to be comfortable and warm, but you don’t want the fabric to be too bulky that you can’t layer above it. It’s a world of personal preference based and every shirt has its own unique. So, I’ll do my best to lay out the best merino wool base layer for men, especially when it comes to specific activities.
There’s no need to bore you with the mundane details (we’ll leave those until the end). So, let’s get right into a quick Merino wool base layer buying guide, our review considerations, and some of our favorite men’s base layers for various occasions.
- Best Overall: Smartwool Classic Thermal
- Silver Medal: Icebreaker Oasis 200 Base Layer
- Best Value: Meriwool Men’s Midweight Base Layer
- Best Ultralight: Patagonia Capilene® Cool Merino Shirt
- Best For Travel: Proof 72-Hour Merino LS Tee
- Best For Winter: Minus33 Men’s Yukon Expedition Wool Crew
- Best For Summer: Ridge Merino Solstice Lightweight Sun Hoodie
- Best 1/2 Zip: Helly Hansen LIFA Merino Lightweight 1/2 Zip
- Best Under $50: Merino.tech Lightweight Merino Wool Base Layer
Disclosure: To maintain genuineness and authenticity, Merino Wool Gear DOES NOT sponsor products. However, as an affiliate member, we may earn a small commission from qualifying purchases.
Quick Merino Wool Base Layer Buying Guide
Before you go investing your hard-earned money on a high-quality Merino base layer, you should briefly understand what traits to explore. Remember, unless you’re thru-hiking or one-bagging it across the world, you will only be wearing your base layer for specific situations. For instance, you probably won’t be wearing it to the office – unless your like me and work wherever life takes you.
Anyways, don’t get too excited and throw away your savings on Merino wool without doing your due diligence first.
Comfort
It doesn’t matter how great a base layer looks; your top buying consideration should be comfort and fit. With Merino wool, you don’t have to worry about itchiness or irritation, as it’s a tremendous next-to-skin fabric. That is to say, if you get irritated by stitching, look for products with flatlock seams.
Temperature Regulation
It’s not always about warmth when it comes to a quality base layer. What you should look for is how well the material regulates your microclimate. So, it should keep you cool when it’s warm and warm when it’s cool. Oh yeah, and dry. Typically, the higher fabric weights are more heated but less breathable.
Functionality
You don’t want to spend a bunch on a base layer and only use it for specific cases (or maybe you do). Either way, you should understand if your shirt is made for particular activities (winter sports, etc.) and can also be worn as a standalone piece. As a result, check out the overall style and fit to better gauge your decision.
Durability
Lastly, you’ll want to make sure that your base layer lasts you a long time. I mean, some of these things cost over $100; they should last you nearly forever. However, pure Merino wool apparel is known to be delicate if not cared for properly. You can still get good strength and durability from them, but blended fabrics are more robust.
Best Overall Men’s Merino Wool Base Layer
Smartwool Classic Thermal Base Layer
100% Merino wool | 250 gsm | Slim fit | 16 colors | Price: $$$$
Pros: “Gold Standard” of base layers | Versatile | Engineered fit & updated features
Cons: Not suitable for hot weather | A bit on the expensive side
I’ve always found the term ‘best’ to be a bit subjective. But, when it comes to industry-leading Merino wool base layers, the gold medal goes to the Smartwool Merino 250 Base Layer.
There are little frills, but this shirt is packed with features. The 100% Merino wool construction is soft and comfortable, while the 250 gsm thickness hits the warmth-to-weight sweet spot. Moreover, there are flatlock seams and engineered shoulder panels to reduce seam irritation.
And it’s not just the quality of the fabric; the fit has been engineered over the years for better functionality. Smartwool has trimmed down the bagginess of their clothing. As a result, they have created a slimmer, more ‘layerable’ fit. They even added a bunch of colors and styles so that you can wear this long sleeve as a standalone piece.
On the other hand, I must lay out some of the negative aspects of this Smartwool Base Layer. For one, the midweight fabric may be a bit thick in the summer, so you may not be able to use this year-round. Secondly, it’s a tad expensive, even for base layer standards. But I still think it’s worth every penny.
Above all, Smartwool is a leader in the Merino wool industry, and their 250 base layer lives up to their reputation. If you can check one out today or even want to look at their similar 150 base layer – you can do so below.
Silver Medal: Men’s Merino Wool Base Layer
Icebreaker Oasis 200 Base Layer
100% Merino wool | 200 gsm | Athletic fit | 7 colors | Price: $$$$
Pros: Minimal seam irritation | Fantastic versatility | Breathable yet protective
Cons: A bit thin for frigid temperatures | Delicate laundry process
Icebreaker is quite possibly one of my favorite Merino wool companies. Not only do they make quality products, but they take their environmental responsibility very seriously. Likewise, Icebreaker provides comprehensive transparency reports so that consumers can peak into all aspects of their business. Let’s take a lesson from them in honesty to offer you our silver medal base layer for men: the Icebreaker Merino 200 Oasis Base Layer Crewe.
I’ll start with the Merino wool material itself. Icebreaker crafts their Oasis crew with 100% pure Merino wool, sourced ethically through ZQ Merino. The fabric density is 200 GSM (hence the Oasis 200 name), which I consider lightweight. Subsequently, it’s perfect for cool to warm conditions, but you may need something a bit thicker if you are outside in the winter.
If the high-performing material isn’t enticing, then Icebreaker’s engineered fit and construction may do the trick. Across the entire garment, they use flatlock seams to reduce irritation. Moreover, the shoulder seams are offset with gussets, so there is no top seam on your collar bone. As a result, it’s perfect if you’re wearing a backpack for long distances. In addition, the back of the shirt is a bit longer than the front to provide a thin layer of warmth to your lower back and give you easy access to your pockets up front.
The one thing I think could be improved with this base layer is the overall durability. However, if you’re caring and laundering it properly, it honestly shouldn’t be an issue.
To sum up, if you’re a trail runner, cross trainer, or just want an incredible three-season base layer, make sure to check out the Icebreaker Merino 200 Oasis Crewe!
Best Value Merino Wool Base Layer For Men
Meriwool Men’s Midweight Base Layer
100% Merino wool | 250 gsm | Regular fit | 8 colors | Price: $$
Pros: Extremely affordable | Snug fit layers well | Mix of warmth & breathability
Cons: Shoulder seams may be irritating | User-reported durability issues
Functional, comfortable, and affordable, the Meriwool Men’s Midweight Base Layer is an exceptional piece for adventurers on a budget. It costs about 2/3 of some of these other base layers cost but is still around the same quality. Therefore, you can spend a bit more on those uber-expensive ultralight sleeping bags and cuben fiber tents!
I like how this base layer drapes against my body as the snug, elastic-like fit (characteristic of Merino wool) feels super soft against the skin. The 18.5-micron fibers are about the industry standard in thickness, so you are getting the same comfort as you would from similar base layers at a fraction of the price. Finally, the tight fit makes this shirt great for layering, providing a non-bulk, annoyance-free base.
I recommend wearing the Meriwool base layer anywhere from temperatures below freezing to about 55-60 degrees. Although, I don’t think this shirt is suitable for warmer conditions, as the 250 GSM is a bit thicker (in the midweight class) yet still surprisingly breathable.
However, nothing is perfect. I would be doing you a disservice of talking up this base layer without playing Devil’s advocate. Firstly, I feel like a minor design flaw within the shoulder seams causes slight irritation. It’s honestly not that big of a deal unless you are wearing a heavy, heavy backpack. Next, some users have reported durability issues, and small holes are forming. I haven’t seen that myself, but luckily, Meriwool has a solid warranty if any problems are found.
To sum up, I wouldn’t call the Meriwool Base Layer “budget,” but more of a value buy. It’s fantastic to sleep in while you’re tucked in your sleeping bag or layered under your fleece during chilly weather. For the complete set, check out their base layer bottoms, too!
Best Ultralight Merino Wool Base Layer For Men
Patagonia Capilene® Cool Merino Shirt
65% Merino / 35% recycled polyester | ~125 gsm | Slim fit | 3 colors | Price: $$$
Pros: Keeps you cool & protected | High-performance features | Produced sustainably
Cons: Not suitable for frigid environments | XL+ sizing not always available
Patagonia is the quintessential brand for outdoor gear. Their commitment to the environment and ethics is almost second-to-none within the industry. They pay close attention to their impact and adjust even the seemingly smallest of details to lessen their carbon footprint. And, their newly release Capilene Cool Merino base layer exudes their expertise and attention to detail.
The lightweight wool and polyester blend provides the best of both worlds in breathability and durability. At a fabric thickness of 125 GSM, this Patagonia base layer is one of the thinnest on our list but can still take a beating. It provides enhances moisture-wicking and breathability features, keeping you cool even in humid conditions. Moreover, the Merino wool is sourced from the Responsible Wool Standard, meaning it’s harvested ethically and sustainably (we wouldn’t expect anything less from Patagonia).
However, it’s not just the fabric itself that makes the Capilene® Cool Merino Shirt our favorite base layer for hiking. Patagonia has added unique engineering features into the overall construction. There are side vents for additional airflow and even a drop-tail hem for a better fit. In addition, the sleeves are designed in such a way to improve mobility and reduce rubbing. In other words, Patagonia thought of everything to enhance your comfort.
On the other hand, I feel like this shirt isn’t the best for highly frigid conditions. Sure, you can add more than one midlayer, but there are other products available that are more suited for winter hiking.
Note: If you are looking for larger sizes, you should continue to check in with Patagonia for availability as XL+ shirts tend to go quickly. You can also view Patagonia’s size charts here.
To sum up, I genuinely feel like you can’t go wrong with Patagonia. The Capilene® Cool Merino Shirt drapes so comfortably on your body. Also, it is one of the highest-performing base layers on the market!
Best Men’s Merino Wool Base Layer For Travel
Proof 72-Hour Merino LS Tee
87% Merino / 13% nylon | ~150-160 gsm | Athletic fit | 4 colors | Price: $$$
Pros: Ultrasoft fibers | Technical fit | Corespun durability
Cons: Limited color options | A bit expensive
Three days. One badass shirt. The design and testing team over at Proof really knows how to market their apparel. With the Proof 72-hour Merino wool long sleeve tee, you get three days of ultrasoft, no-odor wear, making it the perfect base layer for exploring new countries. If that sounds a little farfetched, don’t worry, Proof put a 72-hour vlog showing how well this LS tee stands up to the wear-and-tear of adventure travel.
The Merino wool blended construction offers extra durability on top of the unique odor-resistant properties. As for comfort, you aren’t going to get much more luxurious. The 16.5-micron fibers create a silky smooth next-to-skin feel while the engineered design minimizes any irritation. It’s definitely one of the comfiest base layers on our list.
Above all, we love how Proof is transparent about their sourcing methods for their LS Merino base layer. They get all their raw wool from Global Merino, an industry-leading supplier. Proof even goes as far as to list the three farms in New Zealand where their Merino wool comes from. Seriously, they even provide the coordinates! Now that is what we call transparency.
To sum up, the Proof 72-Hour Merino LS tee is an excellent choice for digital nomads, adventure seekers, and every other type of traveler. If you don’t like the basic long sleeve style, they make a short sleeve tee and henley, as well! Or, take a look at another one of our reviews of the Top Merino travel shirts for men!
Best Men’s Merino Wool Base Layer For Winter
Minus33 Yukon Expedition Base Layer
100% Merino wool | 400 gsm | Regular fit | 3 colors | Price: $$$$$
Pros: Perfect for extreme conditions | Durable fabric | Soft next-to-skin feel
Cons: Relatively expensive | Launder with care
Are you looking for a base layer to keep you toasty during the coldest winter days? Perhaps you’re trekking into the Sierras and want to be protected during a flash blizzard. Well, then the Minus33 Yukon Men’s Expedition Wool Crew may be your best option.
Designed with pure 400 GSM Merino wool, the Yukon baselayer provides a thick layer of warmth and protection while you conquer the elements. This shirt was designed to withstand the brutal and wintery conditions on New Hampshire’s Mount Washington. In fact, Minus33 claims that their product has been tested in the harshest conditions on the planet and still worked exceptionally. Explorers have used the Yukon layer in the arctic, antarctic, and even at the summit of Mount Everest.
Aside from the protection the Yukon base layer offers, it is one of the most comfortable shirts on this list. The ultra-soft, 18.5-micron Merino wool fibers feel luxurious against your skin. In addition, the flatlock seams and tagless interior reduce irritation so that you stay itch-free while battling the winter elements.
Although I have a few qualms which may just be trivial to you. Firstly, I’m not a big fan of the price point, but hey, you’ve got to pay big for performance. Also, I wish that Minus33 would add more color options other than black (as of October 2022, they also navy & olive) . To me, these issues are minor, but problems nonetheless.
To sum up, if you’re a winter explorer, you should be packing the Minus33 Men’s Yukon Expedition Base Layer in your pack (or even as a mid-layer). Even though we only focus on tops in this review, you can complement the outfit with the Minus33 Katmai Expedition Bottoms for full-body coverage.
Best Men’s Merino Wool Base Layer For Summer
Ridge Merino Solstice Sun Hoodie
87% Merino / 13% Nylon | 145 gsm | Relaxed fit | 6 colors | Price: $$$
Pros: Super lightweight | Exceptional drape | Comfortable oversized hood
Cons: Length a bit long for shorter people | Slight wrinkles form after several use
A hoodie in the summer! Are you kidding me?
Listen, I know this isn’t your typical base layer, but hear me out: the Ridge Merino Solstice Sun Hoodie is 100% legit. Seriously, I’m wearing mine now (in hunter green) as I’m typing.
The super ultralight, 145 GSM fabric feels so minimal against your skin. It drapes nicely over the body, hugging the right places and promoting a full range of motion. The thin material does feel delicate, but Ridge Merino’s mForce technology helps to improve durability.
When I pair the Solstice Hoodie with a mid-layer fleece and packable down jacket, it provides excellent 4-season protection. In addition, the oversized hood can even fit climbing or ski helmets if you need some added warmth. Oh yeah, I can’t forget the flatlock seams and thumbholes. It’s truly an incredible and unique hoodie.
However, we have to mention the good with the bad. As a vertically challenged man, I find the length to be a bit long (even for a size small). But, it’s not that long, just a personal preference. Also, make sure to tie a knot in the hood strings, or you will be consumed with wiggling the line back through the hood after laundry day.
Above all, the Ridge Merino Solstice Hoodie is super functional. You can wear it as a base layer on the trail, a hoodie at home, or even as a standalone piece to the grocery store. Make sure to check one out today!
Best 1/2 Zip Merino Wool Base Layer For Men
Helly Hansen LIFA Merino Lightweight 1/2 Zip
57% Merino / 43% propylene | 215 gsm | Athletic fit | 6 colors | Price: $$$$
Pros: Fantastic temperature regulation | Improved technical design | Dozens of colors available
Cons: Neck hole a bit snug when zipped | One of the more pricey base layers
Helly Hansen is a well-renowned outdoor apparel brand, and they have done it again with this base layer. The unique piece is composed of both Merino wool and synthetic polypropylene. The exterior of the 1/2 zip is made of Merino, offering excellent temperature regulation and comfort benefits. On the other hand, the interior is made of synthetic LIFA, which helps to wick moisture away from the skin. The 2-in-1 construction is genuinely one-of-a-kind.
Moreover, not only does the blended material help with moisture management, but it also improves overall durability. Which, if you’re hiking through the woods in a sea of twigs, bark, and plants, is a must. Even if you aren’t out on the trail, the high-performance fabric feels protective.
However, we feel like the overall comfort level of the Helly Hansen LIFA Merino base layer could be improved a tad. The drape is okay, as the athletic fit helps in the layering department. But, it can feel a bit tight as compared with the other base layers we tried. The sleeves and neck hole openings are slightly small, so you may want to size up if you have massive arms (or traps).
Still, we feel that Helly Hansen did an excellent job constructing this base layer for outdoor enthusiasts. It’s warm, soft, durable, quick-drying, and moderately comfortable; everything you want out of a protective next-to-skin layer. Sure, it may be on the pricier side of the base layer spectrum, but I can honestly say it’s worth every penny.
Best Men’s Merino Wool Base Layer Under $50
Merino.tech Lightweight Merino Wool Base Layer
100% Merino wool | 165 gsm | Regular fit | 9 colors | Price: $
