The 10 Best Merino Wool Base Layers

Published By

At heart, I’m a buy-it-for-life guy. I want to spend hours researching a single item to decide how I can find something that will be a constant standby in my life. So when it comes to clothes, there’s nothing I’d rather have in my wardrobe than a solid set of merino wool base layers.

Why? Because in addition to being ultra tough and long lasting, merino wool base layers are the perfect all-season clothing. When it’s hot, they’ll keep you cool. When it’s cold, they’ll keep you warm. When you get caught in a downpour, they’ll still keep you comfortable. In short: I think merino wool is the best thing since sliced bread.

With that in mind, I’d like to take you on a tour of the best merino wool base layers from brands I’ve grown to know and trust. Think of them as an investment in your long-term comfort and adventure readiness.

Helly Hansen Lifa Merino Heavyweight Half-Zip Base Layer Top

Helly Hansen Lifa Merino Heavyweight Half-Zip Base Layer Top

Norwegian-designed Helly Hansen clothing has a history of over 140 years of success in skiing, sailing, and hiking. And throughout the company’s history, they’ve continued to elaborate on one staple item: Woolen base layers. Their Lifa Merino half-zip top is just what I want when the cold months of the year come knocking. It’s double-layered construction gives all the temperature regulating properties of wool, and augments them with moisture-wicking Lifa polypropylene.

The final result is the best of both worlds, with unbeatable durability and performance. Add in flatlock seams to reduce uncomfortable rubbing and a clean sense of style, and you get a merino wool base layer that you’ll come back to time and time again.

Tracksmith Brighton Base Layer

Tracksmith Brighton Base Layer

Tracksmith’s clothing may be designed with runners first in mind, but it’s stylish and well-made enough to make any outdoorsy type happy. But since they are made with runners in mind, you can reap the added benefits of completely seamless construction—making their Brighton base layer the most comfortable merino wool top I’ve ever seen. It’s like wearing your favorite pajamas, but being able to be out in public while you’re doing it.

The odor control is top notch, and ventilation built into the chest makes the Brighton perfect for extended physical exertion. Wear it solo during the spring and summer, or layer it up for fall and winter temperature regulation.

Icebreaker 150 Zone Long-Sleeve Crew Shirt

Icebreaker 150 Zone Long-Sleeve Crew Shirt

Pure merino wool has long been the golden child of outdoor clothing. But as companies have tested and iterated on their 100-percent wool designs, it’s become obvious that blending a little bit of other materials in can lead to better performance. Icebreaker was one of the first to do this, and their 150 Zone crew shirt is a perfect example. It’s made of 83 percent merino wool, 12 percent nylon, and 5 percent spandex—giving it a near-perfect blend of temperature control, moisture wicking, durability, and comfort. The addition of UPF 20 treatment for the fabric is especially nice for full-sun activities, protecting both you and the fabric from harmful UV rays.

Kuhl Cashmerino T-shirt

Kuhl Cashmerino T-shirt

If you think that merino wool is reserved only for outdoor activities like hiking and biking, think again. Kuhl’s Cashmerino T-shirt takes the softness of the highest-grade merino wool, and puts it into a casual fit t-shirt that you’ll never want to stop wearing. A little bit of nylon helps it keep its shape better than pure merino clothes, giving it better structure around the shoulders and through the chest. Wear it more, wash it less, and enjoy the skin-soft luxury of merino every single day.

Odlo Natural + Kinship Warm Base Layer Top with Face Mask

Odlo Natural + Kinship Warm Base Layer Top with Face Mask

When it gets really cold, look towards Oldo Natural + Kinship’s base layer. It’s one of the few merino wool blend layers to feature an integrated face mask, making it ideal for winter sports wear. The fabric blend puts merino front and center, then supports it with polyester, polyamide, and elastane to create natural body-mapped ventilation zones.

That means it’ll keep you warm where you want to be warm, and cool where you want to be cool. And that performance is all topped off with a fully seamless construction, ensuring complete next-to-the-skin comfort. 

Smartwool Merino 150 Base Layer Long-Sleeve Shirt

Smartwool Merino 150 Base Layer Long-Sleeve Shirt

Lightweight and surprisingly affordable, the Smartwool Merino 150 shirt has become my go-to recommendation for all-season hiking gear. Merino wool is wrapped around a nylon core, giving these shirts both excellent durability and resistance to becoming misshapen.

The offset shoulder and side seams make sure that you can carry a heavy pack without inviting chafing, too—just another reason that it’s the best merino base layer for camping and hiking. The whole shirt is eco-friendly, too, from the production processes to the wool sourcing to the plant-based dyes.

Filson 280G Merino Long Sleeve Crew and Bottoms

Filson 280G Merino Long Sleeve Crew and Bottoms

Having lived in both the Northern and Southern United States, I understand the importance of matching your clothes to your environment. And while lightweight merino base layers are usually called for as a year-round staple, there’s no substitute for heavyweight tops and bottoms if you’re dealing with a Minnesota winter.

Filson’s 280G long sleeve crew and bottoms are the way to go, coming in at nearly double the weight of each option listed above. That’ll keep you warm through an entire winter when used as a layer, and comfortable in the coolest months of spring and fall on its own.

Patagonia Capilene Air Crew Base Layer Top and Bottoms

Patagonia Capilene Air Crew Base Layer Top and Bottoms

Blending merino wool and recycled Capilene polyester in nearly equal portions, Patagonia has made one of their finest layering pieces yet. The 50/50 blend takes the best aspects of thermoregulating wool and quick-drying polyester to give you a single layer that can be worn year-round—even in the heat of a desert summer.

Both the tops and bottoms are made with entirely seamless construction and elastic knit in the cuffs, allowing them to keep their shape without giving irritating friction points. I’d gladly wear these while out on the trail, or on an inner city urban exploration.

REI Co-op Merino Midweight Base Layer Crew Top and Bottoms

REI Co-op Merino Midweight Base Layer Crew Top and Bottoms

Want the wool without the price tag? Get these REI Co-Op tops and bottoms while you can. They’re currently discontinued, but the company has quite a backstock to get through—so they’re deeply discounted for the best price you’re ever likely to pay for merino wool. Both the tops and bottoms are made from 100 percent merino wool, with flat seams and gussets for maximum comfort and range of motion.

The shirt has a droptail hem that works perfectly with pack belts, while the bottoms have a low profile elastic waistband that stays comfortable under all your other layers.

Stoic Merino Blend Crew Top and Calf-Length Baselayer Bottom

Stoic Merino Blend Crew Top and Calf-Length Baselayer Bottom

And as a more available alternative to REI’s in-house brand, the Backcountry exclusive Stoic base layers offer a merino/nylon blend at an exceptionally affordable price. They’re both manufactured to 100 gram insulation weight, making them lightweight and flexible for all-season layering.

Each piece is made to be form-fitting at your usual size, so order up if you’re looking for a looser fit. The whole Stoic base layer series is available in four bright and vibrant colors, too—which is a rarity among the natural color dominance in this garment style.

Disclosure: Clicking on these links and making a purchase may earn us a small referral fee, at no extra cost to you. Learn more here.

Join The List.

Subscribe and get the latest goods straight to your inbox.