Merino wool is a super fiber. The best merino wool clothing somehow manages to be comfortable in 95-degree heat, and merino base layers keep you warm well below freezing. Unlike synthetic fibers derived from petroleum, merino wool is natural and renewable.
Merino wool’s versatility means there’s a bewildering array of blends and options to choose from. Here are our favorite merino wool products that we’ve tested by wearing and washing (usually in cold water, and hung to dry, although we do machine dry them just to see what happens) over the course of months and even years in some cases. Once you’re done here, don’t forget to check out the rest of our apparel guides, like the Best Merino Wool T-Shirts, Best Base Layers, Best Puffer Jackets, Best Hoodies, and Best Hiking Boots.
Updated November 2025: We’ve added several new T-shirts from Huckberry’s Proof brand and Taylor Stitch, a Minus33 base layer for extreme cold, Ridge Merino’s excellent Cloudripper merino-grid fleece blend, Wool&’s Roam Convertible Wrap Bra, and Proper Cloth’s exquisite dress shirt.
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Why Is Merino Wool So Great?
Merino wool is great because you’re stealing a sheep’s ability to keep itself warm or cool based on the temperatures it’s in, a process often referred to as thermoregulation. If you’ve only ever worn the sort of itchy wool sweaters your proverbial grandmother supposedly made, you might wonder what all the fuss is. The answer is that Merino sheep have thinner, softer wool, which has evolved to keep them comfortable across a wide range of temperatures and is comfortable to wear next to your skin. Wool is sustainable, too.
One sheep can produce 4 to 5 pounds of wool per year. That’s because the sheep that make merino wool drink only the purest alpine waters and study the art of comfort under the tutelage of those stuck-up Pashmina goats, who, let’s face it, might know a thing or two about wonderfully pillowy softness. Just kidding. Merino sheep do have that softer wool though, and merino wool is a remarkable fabric that’s become the cornerstone of my wardrobe.
Merino wool comes in different weights, which you will frequently see listed as “200 gsm” or something similar. (The “gsm” refers to grams per square meter, sometimes listed as g/m.) What’s important is the scale and where your garment falls on it. At the low end, you have T-shirts and underwear, which are typically 150 gsm, though we have seen some as low as 120 gsm. Generally, anything below 200 gsm will be a good base layer or T-shirt. From 200 to 300 gsm are your mid-layers, and anything above 300 is a heavier garment.
If you’re more familiar with synthetic ratings like those often used on fleece, know that, in my experience, about 120–160 gsm wool corresponds to 100-weight fleece, 160–200 gsm wool roughly matches 200-weight fleece and 200+ wool is like 300-weight fleece. In every instance, the wool is warmer because it’s better at trapping heat, especially in the wind. (That said, there are reasons to go with fleece at times, like how incredibly lightweight it can be.)
Nuyarn is a merino wool/synthetic hybrid weave, wherein merino wool is wrapped around a nylon core for warmth, lightness, and extra durability. The idea is to get the temperature regulation benefits of merino, but to add some of the longevity of nylon. In my experience, Nuyarn mostly works. It’s our top pick for base layers, though I find it less necessary in more casual garments, where I prefer 100 percent wool.
How to Care for Merino Wool
Most merino products will have care instructions. Most likely it will be to wash cold and lay flat to dry. The latter is important, as hanging wool to dry will stretch it out (because of the water weight). While most merino labels say the garment can be machine washed, my experience has been that hand-washing merino will extend its life. This is particularly true of very lightweight (150 gsm) merino base layers and T-shirts. The exception is Minus33’s Microweight Raglan short sleeve T-shirt, which is machine-washable and dryer-friendly. Having done both to mine for over a year, I can vouch that it does indeed hold up.
I’ve never had a problem storing merino in my closet between wears, but for long-term storage, I recommend you take precautions against moths, which are notorious for eating holes in wool. I have lost merino garments to moths.
If you don’t want to smell like mothballs, there are better solutions. I make sure to wash and thoroughly dry whatever I am storing, then I seal it in a compression bag, like this. Another option is to put your merino garment in a cotton bag or otherwise wrap it in cotton and then put it in a plastic bin. It’s very important to make sure that the garment is completely dry before using any of these storage methods, otherwise your wool will smell musty and moldy. Other options include storing your garment in a cedar chest, which is a good natural deterrent for moths, or use moth traps or lavender sachets, which will repel the moths.
100 Percent Merino vs. Blends
Should you buy 100 percent merino or should you go for a blend? The answer is … it depends. On the garment in question, the use case, and your preferences. Probably the best way to find out is to try several and see what you like. One advantage to blends is that they’re stretchy, which makes them better for active pursuits like hiking, rock climbing and the like. I like 100 percent merino for heavier mid-layers like hoodies or jackets, but I prefer blends for lighter layers. My experience has been that the closer I get to my skin, the more blend I want, with Nuyarn being my top pick for base layers.
There are also some alpaca blends out there that are also wonderfully soft (I love everything I’ve tried from Paka and Arms of Andes). If you’re one of the rare people who do find merino itchy, you might be allergic to lanolin, which is the skin oil produced by sheep. Alpacas don’t make lanolin, and the fibers are thinner and finer than merino. That makes alpaca warmer and softer, but it’s also more expensive.
Merino vs. Synthetic Fibers
Which is better? The answer again is … it depends (sorry). But usually merino. By synthetics, I generally mean polyester, nylon, polypropylene, rayon, or blends of these and other fabrics—everything but cotton, wool, and linen.
Synthetics generally win for wicking away sweat, which means they tend to feel drier. They also tend to dry faster, so when it comes to things like socks and underwear, even most “merino” options are often more than 50 percent synthetic. Synthetics are just better at handling moisture. How much this matters depends on a host of personal factors. For example, I feel weird and almost clammy in anything synthetic, so I don’t really care how much moisture it wicks away.
The downside to that moisture wicking is that synthetics retain odor. There are some chemical treatments that can help, but I’ve never tried anything synthetic that was as odor-resistant as merino wool.
Another difference is breathability. Synthetics are passable in this department, but it’s where merino really excels. If you’re hot and are hiking up an exposed slope toward an open pass and then dropping down into the cool of a forest, merino is your friend, because the breathability means less sweat to cool you when you get out of the sun. Again, how much this matters depends on your body.
The final factor worth thinking about is durability. In some cases, synthetics will last longer than pure merino, particularly in scenarios where abrasion is a major source of wear. To my mind, this is just another reason to choose a merino blend rather than going all the way to synthetics, but it’s something to think about if you do a lot of off-trail hiking or rock climbing—any activity where your clothes are going to take a beating.
Base Layers
To really see how remarkable merino wool is, start at the bottom, with the clothes next to your skin. Merino really shines as a base layer. It’s warmer for the weight, wicks moisture well, and unlike synthetic fabrics, merino stays stink-free for days of wear. Be sure to read our layering guide for more on how to put it all together and stay comfortable in any weather. We also have a separate guide to the best base layers if you want know all your options, but here are our top merino picks from that guide.
Best Lightweight Base Layer
Ibex Woolies Pro Tech base layer crew is the best lightweight merino base layer we’ve tested. If you want a hard-wearing shirt, this it it. Woolies are Nuyarn (see above), which is 85 percent merino wool and 15 percent nylon—the merino wool is wrapped around a nylon core, which increases the warmth while being lighter (5 oz for the men’s large) and more durable. This is my top pick for all things technical. It’s what I bring hiking, backpacking, and it’s reviews editor Adrienne So’s pick for running, climbing and other high-aerobic activities when it’s cold. I also love the Woolies Pro Tech Bottoms ($115), which are what I bring backpacking in all but the warmest of weather. There’s also a quarter zip version of the shirt if you prefer.
Aside from comfort and warmth, a bit part of the reason we recommend Woolies is that they last. Ibex is what passes for a heritage company in this space; the company was founded in 1997 and has been cranking out merino garment for a long time. Adrienne’s parents bought her two sets of Ibex base layers in 2001 that she still wears today, in the year of our Lord 2025. Properly cared for, Woolies will keep you comfortable warm for years to come.
Best Heavyweight Base Layer
When I want something a bit warmer than the lightweight Woolies above, I reach for Smartwool’s Classic long sleeve base layer. These may be the most popular merino shirts around, and for good reason: They’re very comfortable, tending to the looser side, feature heavy duty seams that don’t rub, and sit off the shoulder for more comfort when wearing a pack. At 87 percent merino wool (blended with nylon), these are also very durable while remaining lightweight (10.3 oz for a men’s large). This Smartwool shirt, along with the matching pants ($115), are great for chilly winter days.
The picks above all have what my wife calls “that sporty look,” which the industry refers to as “technical.” This 100 percent merino shirt from Unbound is the opposite: it just looks like a long sleeve shirt. It’s incredibly soft and while it does pill a bit if you run it through the dryer (don’t), it’s proved itself plenty durable—I’ve been wearing it constantly for over a year now and it still looks like it did when I got it. It’s the long-sleeve, base layer twin to our favorite T-shirt (see below). It’s on the thin side for a base layer, which makes it perfect for those cool weather mornings in the shoulder seasons. It’s versatile too; it can be used as a base layer, but it also works as a T-shirt when it’s not too chilly. Fit runs true to size, and if the one you want is sold out, be patient; Unbound frequently updates its stock.
There are so many! Here’s a few more to consider, but really, go read the base layer guide.
Merino Mid Layers
Fleece has its place, but I rarely wear it these days. I prefer merino for my mid layers. It’s better at helping your body regulate its temperature. The one place fleece still wins for me is backpacking, it’s almost always lighter for comparable warmth, at least in mid layers.
Like the Northern Lights or the McRib, the thickest Ibex wool hoodie appears irregularly and with some fanfare. The Mammoth Hoodie is indeed a big, furry beast of a garment—it’s basically the weight of the classic American Giant hoodie but made of 85 percent wool cut with 15 percent nylon for added warmth and stretch. Ibex says it’s the warmest hoodie they’ve ever made, and in my week of testing, I’ve used it in place of a jacket in mid-30s temps. It has an athletic cut with zippered pockets and thumb holes. I do wear a stocking hat with it in the cold because the scuba hood is meant to fit under a helmet which means it’s too small to provide enough warmth for my large shaved head on its own. —Martin Cizmar
There’s a dearth of merino wool for kids. Perhaps the price for something that kids may outgrow in a few months makes the economics unappealing for manufacturers. Whatever the case, very few companies offer kids-size merino. In fact, this Minus33 hoodie isn’t available in kids’ sizes, but the extra-small women’s fit my 10-year-old perfectly and continues to fit her as an 11-year-old. You’ll want to check the fit chart on Minus33 for your own kids, but if they do fit, this is a fantastic hoodie. It’s plenty warm (and my daughter is always cold) and durable enough to stand up to kid life, climbing trees, and running through the woods, and the hand warmers pair well with mittens on cold days. Best of all when kids are involved, this one can be machine-washed and tumble-dried. It won’t shrink or lose its shape, and the colors won’t bleed.
The Best Merino Jacket
A growing number of studies have shown that there are PFAs—hormone-disrupting chemicals that are commonly used in a number of plastics—in ordinary sportswear, like leggings and sports bras. If you, like me, are on a quest to replace your polyester clothing with natural fibers, then Ibex’s 100 percent merino wool Shak Jacket is the natural candidate to replace your (my) worn-out Patagonia Better Sweater ($159).
I took this jacket on a trip this spring to Ireland. It’s surprisingly dense and soft to the touch. It kept me warm on blustery 30-degree days, layered easily under my rain jacket and over my tank top, and looked sleek enough to go out to dinner. In western Ireland, at least (“I like your jumper!” said many an Irishman). It doesn’t pack down quite as compactly as a synthetic layer might, nor is it as light, but it looks much nicer and it won’t feel like slime on your skin when it gets wet. (The full-zip version is currently out of stock, but Ibex notes that it will be back soon.) —Adrienne So
The Best Grid Fleece Merino Jacket
Grid fleece is awesome. It’s warm for the weight, and very breathable, making it great for highly aerobic activities. Despite all that I prefer the comfort of merino, and bring my merino mid layers backpacking even though there’s a definite weight penalty. Thanks to Ridge Merino’s Cloudripper jacket though, I can now have my merino and eat my grid fleece too. Ridge has combined grid fleece with merino wool to give you the advantages of both, keeping the merino against your skin, but using grid fleece to improve ventilation and make the jacket much lighter. The men’s large I’ve been testing weighs just 16.1 ounces on my scale. That’s 4 ounces more than Patagonia’s R1 Air hoodie ($189), probably the most popular grid fleece jacket out there, but I have found the Cloudripper to be considerably warmer than the Air.
The Cloudripper jackets (there’s also a 1/2 zip version and a crew neck version) are made of two fabrics. The first is wool grid fleece (265 gsm) which is 69 percent merino, 15 percent recycled polyester, 13 percent nylon, and 3 percent spandex. The secondary fabric is a grid fleece(180 gsm) that’s 51 percent recycled polyester, 41 percent Merino wool, and 8 percent lycra. The more traditional grid fleece with the higher polyester count is used mainly on the hood and lower back, while everything that would touch your skin (if you don’t have on a base layer) is merino.
I’ve been testing the full zip Cloudripper for about a month now, and it’s quickly become my go-to mid layer on the cool fall mornings and evenings that have settled in where I live. It’s proven itself on some early morning bike rides, where it strikes a balance between keeping me warm when I’m first starting out, and venting off the excess heat I’m generating once I get going. It also doesn’t get stinky like my purely polyester grid fleece. I’m still in the process of putting together a dedicated guide to mid layers, but the Cloudripper is an early contender for best grid fleece. It’s the best of grid fleece, married to the best of merino wool to create what might be the ultimate technical mid layer.
If you have concerns about using goose down jackets as an insulation layer, merino wool is also a decent substitute for synthetic insulation. Vests are like the cheat code of layering if you like to keep your core warm but your arms mobile, or you want to get an extra soupçon of warmth without adding too much bulk. I like to layer Ibex’s Wool Aire Vest under my regular wool coat or rain shell, if I’m going out for the night or on a long run. —Adrienne So
The Best Merino Wool T-Shirts
Wool might not seem like a good choice for a summer T-shirt, but merino is surprisingly comfortable even when it’s warm. To a point anyway. On humid days over about 90 degrees Fahrenheit, I usually go with cotton or linen, but anything under 90 and I’m wearing merino. There are far a ton of merino T-shirts out there, so many in fact that we now have a guide dedicated to just the best merino t-shirts. Here are our favorites from that guide.
The Best All-Around Merino T-Shirt
Huckberry’s Proof-brand 72-hour Merino T-Shirt is my favorite all-around merino tee. The cut and style are not overly sporty, making it more versatile than a more technical tee. It’s an incredibly soft T-shirt, thanks to the 150-gsm weave of superfine merino wool (16.5 micron). It’s a blend, 87 percent merino and 13 percent nylon, which gives it some stretch—with the trade-off that it will start smelling sooner than a 100 percent merino T-shirt. In the year or so I’ve been wearing it, I’ve found the name accurate. You can get about three days out of it before it needs a wash (depending on ambient temps and what you’re doing, but generally speaking this one will go three days).
I really like that this shirt comes in a wide variety of colors, more than any other shirt I’ve tested. Proof uses the exact same fabric to make long sleeve tees, as well as polos and henleys, if you’re looking for something more than a T-shirt.
The Best Technical Merino Wool T-Shirt
OK, but what about when you do want a more technical cut, with flatlock stitching and offset seams? When I’m heading out hiking, backpacking, paddleboarding, just about anything outdoors, this is the T-shirt I reach for first. It’s lightweight (84 percent 145-gsm merino, 16 percent synthetic) jersey knit is soft and comfortable—not too hot in the sun (it’s also UPF Rating 20), warm enough when it’s cool. It’s also durable (I’ve been rolling jiu jitsu in this shirt for years and it’s fine) and machine washable. You can even throw it in the dryer, no need to baby this T-shirt.
The Most Luxurious Merino T-Shirt
As I say in our guide to the best merino T-shirts, if I could have only one merino T-shirt, it would be this one. It’s the softest, most luxurious merino shirt I’ve tested. It’s 95 percent merino wool, meaning it can go quite a while before it smells, and it’s great when you want to travel light—bring two of these and that’s all you need in half the world. Did I mention how soft this is? It reminds me more of cashmere than merino. Taylor Stitch says that’s because it uses a mercerization process on its wool. Whatever the case, it is soft. Very, very soft. My only real gripe here is the very limited color selection. Taylor Stitch typically has a heather blue and heather black available all the time, and every now and then some other colors will be available on a very limited basis.
The Best Merino Wool T-Shirt for Travel
Unbound Merino’s T-shirt has long been a favorite of WIRED readers, and it’s long been a favorite of travelers. It’s very soft, and because it’s 100 percent merino wool it’ll stay odor free longer than any blended shirt. It’s also lightweight and packs down to a tiny roll, which is perfect if you’re looking to simplify down to one bag (really, is there any other way to travel?). I love how soft these shirts are, and they dry the fastest of any merino T-shirt I’ve tested.
The Best Women’s Merino T-Shirt
Artilect’s blend of merino wool and Tencel (a fiber made from eucalyptus) is shockingly lightweight and versatile. This summer, the Utili-Tee became my favorite shirt for climbing and backpacking. It was soft and comfortable when I was in the tree shade, and then magically stayed light and breathable when I broke through the tree line and the temperature suddenly rose by 15 degrees in the sunlight. The flat seams didn’t cause chafing on my shoulders or waist through backpack straps or a harness, and even though it’s a flattering slim fit, it didn’t constrict the movement of my shoulders or arms in any way. —Adrienne So
Socks, Underwear and Bras
You could argue this is the true base layer, but we’ll skip that and just say that merino wool underwear, socks, and bras are so much nicer than their synthetic counterparts. The caveat is that while merino wool is very soft, most products in this category are blends, usually with some form of nylon. Still, if you haven’t tried merino underwear yet, you’re in for a treat. After testing dozens of each, these are our favorites.
Darn Tough socks are a WIRED favorite. They’re great for skiing, hiking, climbing, and just about anything else you want to do. These blends vary by weight, but most of them are around 50 percent nylon and 50 percent merino, which makes them dry a bit faster than pure merino while remaining plenty warm and comfortable. Darn Tough’s socks also last. Mine are going on two years now without a worn area or hole in sight. If you do develop holes, Darn Tough socks come with a unconditionally lifetime guarantee. You can return them for another pair, no receipt needed, which is kind of crazy if you consider the abuse that hiking socks take.
Minus33 socks are my personal favorite merino socks. I have several pairs of the lighweight and midweight and even one pair of the expedition, though those are so thick and warm I rarely wear them (they’re perfect with the temps drop below 0F though). My favorite are the Lightweight Mountain Heritage Boot Wool Socks, which are perfect for hiking or wearing around town. Minus33 doesn’t publish a blend breakdown for these, but I would guess they’re about 60/40 wool to nylon, with plenty of both softness and stretch to them.
The Best Men’s Merino Underwear
The phrase “wool underwear” might conjure images of some lumberjack from the 1800s with hair growing through the weaves of his itchy, hot long johns, but that’s not what the merino underwear we’ve tested is like. In most cases these are blends, with some nylon as well.
Thanks to WIRED readers for pointing out Woolly to us. These 100 percent merino (190 gsm) boxers are fantastic and affordable. They ventilate well and adjust to changing conditions to keep you comfortable even on days when the weather starts hot and ends cold, or as I like to call it, hiking in the mountains. They’re on the shorter side with a 4-inch inseam, but Woolly makes the same thing in a longer cut.
These are the only 100 percent merino underwear I’ve tested (there’s elastic in the waistband, but it’s surrounded by wool), and they’re also some of my favorites, especially in cold weather. These are longer than any of the other boxers I’ve tried. These are 170 gsm, making them a little lighter, but because they merino content is higher, these are the warmest I’ve tested. After years of testing merino underwear, these are my favorite on all but the hottest days.
Other Great Men’s Underwear:
The Best Women’s Merino Underwear
Branwyn makes what they call merino wool performance sets. I am a fan of Branwyn’s clothes, all of which are Oeko-Tex 100 certified, which means every component of the clothing has been independently tested against a list of up to 350 toxic chemicals. This is one of the most widely known and respected labels for consumer safety. These fit true to size. (I suppose it’s important to note here that I’m a small-busted woman, and that Branwyn makes a Busty Bra ($58) if you need more support.)
However, this is not quite supportive enough to go running, which is why Branwyn launched the Racerback Bra ($75). It’s pretty impressive that Branwyn got merino wool to be compressive enough for medium impact activity. I like that it offers full coverage, with no annoying small and twisty straps and no padding. It precludes the need to change from cotton “everyday” underwear to tight nylon “sport” underwear every time I want to do something active, which is all the time. —Adrienne So
Other Great Women’s Underwear:
The Best Everyday Merino Clothes
I’ll confess that when I launched this guide years ago I thought of merino wool mainly as an outdoor-related fabric. It is great for that, but I’ve since discovered that merino is good for everything, especially travel, since it can be worn several times without any odors. I’ve tried merino pants, dress shirts, workout clothes, hats, and more. The best stuff I’ve tested is below.
The Best Merino Dress Shirt
Proper Cloth’s Reda dress shirt is one of the nicest things I’ve ever tested. The photographs really don’t do justice to how good this shirt looks in person. As you would expect from merino, the Reda is nicely breathable, much lighter and more breathable than your typical dress shirt. I found it quite comfortable even in the summer humidity. The Reda fabric is thin, though, and moisture wicking, which means you do see some arm pit sweat when it’s warm. The good news is of course it won’t retain any smells.
I strongly suggest babying this one a little bit. I machine-washed cold and laid it flat to dry (which was quite quick), but you’ll likely want to give it a light pressing to get it wrinkle free. If you’re traveling, packing these down will get you a few wrinkles, but it’s nothing you can’t get out pretty quickly. The big question I had going in was, how durable will this be? Given the thin fabric, and the sometimes fragile nature of merino when spun this fine, I expected there to be some obvious signs of wear pretty quickly. Fortunately, I was wrong. More than three months of steady use now has done nothing to this shirt, it looks as good as the day I got it.
These super comfy, casual sweatpants from Ridge Merino are some of the most comfortable pants I’ve ever worn. I don’t often work out in them, I’ve never actually jogged in them (or yogged, it might be a soft j), but they’re great around the house. These are 100 percent merino wool (275 gsm) with what Ridge calls a terry fabric (they feel like sweatpants).
This button-down long-sleeve shirt from Woolly is much more casual than the Proper Cloth shirt above. It’s more what you might call business casual. It’s comfortable, soft, well-made, and has the 100 percent merino advantage of being odor-resistant. The only thing I am not quite so fond of is the slightly shimmery look, but that’s just personal preference.
