10 Best Smartwool Socks Compared & Reviewed
Smartwool is a Colorado-based company that started with the simple mission of keeping feet warm in extreme climates. For over 20 years now the company has been pushing the boundaries of what Merino wool can achieve. Merino wool is made from exceptionally fine fibers, it’s the softest wool you can get, and it is completely biodegradable. The benefits of Merino wool are lofty, including superior breathability, wicking, supported temperature regulation, strength, odor resistance, natural sun protection, and quick drying. These factors make Merino wool socks a top choice for sports and hiking. To keep customers happy, Smartwool offers a two-year 100% satisfaction guarantee.
In recent years, Smartwool has introduced some excellent new technologies in Merino wool clothing. One of the most notable is their patent-pending construction method deemed Indestructawool technology. This technology seriously boosts durability without interfering with comfort, bringing you stronger, more capable, yet still cozy socks.
- PhD Outdoor Mountaineer
- Graduated compression
- Mountaineering Extra Heavy Crew
- Very warm
- PhD Outdoor Light Crew
10 Best Smartwool Socks
PhD Outdoor Mountaineer
The PhD Outdoor Mountaineer is a heavier weight sock, offering variations in cushioning to provide the best comfort and performance. You’ll find high-density cushioning where socks take the biggest hits: in the heel and toe. The leg portion of the sock offers a flat knit on the leg, making this sock just right for functioning ideally in low-volume mountaineering boots.
The PhD Outdoor Mountaineer is 14 inches tall, resting just over the calf. 20-30 mmHg graduated compression optimizes recovery once your adventure is done. The socks feature Smartwool’s 4 Degree elite fit system for a perfectly tuned fit. This unique system utilizes two elastics for increased stretch and to keep the sock put. Smartwool’s Virtually Seamless toe offers additional comfort and reinforcement in this sensitive area.
A flex zone at the ankle provides ultimate flexibility. Built-in mesh areas create breathability. You can count on the PhD Outdoor Mountaineer’s 50% Merino wool construction to keep you dry and cozy. These socks are great for long hikes and bike rides, mountaineering, and for any activity in super cold temps. They can also help prevent swelling while traveling on long flights!
Why this sock is a bit pricey, it is an excellent choice for extreme activity and conditions. This is a serious sock for the hardcore adventurer. The support you get from the sock makes it totally worth the price tag.
- Graduated compression optimizes recovery
- Super supportive for long adventures and scaling rough terrain
- Excellent warmth for cold conditions
- Two-elastic system provides a tailored fit
- Stays in places
- Indestructawool technology
- Can be challenging to get on and off (they are compression socks)
- Too warm for summer months
Mountaineering Extra Heavy Crew
As the name suggests, these socks offer extra heavy cushioning, designed to provide maximum impact absorption and warmth for mountaineering quests and other adventures. The whole sock body is supremely thick, gifting your feet and calves with complete coverage and total warmth.
These socks offer a crew fit, landing just over the bulk of the calf. Ankle and arch braces keep the sock in place. A flat knit toe seam keeps your toes comfy and protected. These socks are super thick, super soft, and super warm. They are so comfortable you could wear them as your winter slippers. Plus, they aren’t scratchy!
The high wool content in these socks keeps your feet dry all day and night. Mountaineer, climb in the ice, hit the trails for days on end, and stay toasty even in the bitterest cold of winter. But they’ll also keep your warm during stationary activity, such as waiting for a bus on a cold day. These socks can be worked hard, so don’t be afraid to take them on your wildest of treks.
These socks are a little less pricey than the somewhat similar PhD Outdoor Mountaineer. The trade-off for a lower cost is uniform cushioning as opposed to various cushioning and graduated compression. But, sometimes you truly want a sock that’s super thick all around. For these times, the value of the Mountaineer Extra Heavy Crew can’t be beat.
- Ultra warm, soft, and thick
- Excellent for extreme cold
- High wool content
- The elastic at the top of the sock can wear out over time, potentially leading to a sock that is baggy and might not stay up well
PhD Outdoor Light Crew
Light cushioning offers the comfort and protection of a wool sock without the bulk of heavier models. The heel and forefoot have a little extra cushioning for added protection while trail running or hiking, while the rest of the sock is thin.
Like other socks in the PhD line, the Outdoor Light Crew has a performance fit. Crossed elastic system keeps the sock in place while maximizing flexibility. Smooth toe fit keeps your toes happy. 56% merino wool construction offers the benefits of wool while allowing room for the flexibility that comes from synthetic fibers.
Mesh ventilation optimizes breathability and keeps moisture at bay. This sock is ideal for year-round use in a variety of weather conditions, from summer warmth to extreme winter cold. These socks will stay put and prevent toe blisters no matter how active you get, weather your trekking varied trail or road terrain.
These socks boast an average price for Smartwool. These socks are designed to last, and we think their high quality justifies the investment.
- Excellent breathability
- Stay put
- Good for year-round use
- Lightweight fits well in various shoe types
- Indestructawool technology
- These socks fit a little bit tightly, especially around the ankle, which some folks find uncomfortable after a full day of hiking
- May be a little warm for hotter climates
Trekking Heavy Crew
The Trekking Heavy Crew offers heavy cushioning to handle significant impact and lengthy excursions. This sock is uniformly cushioned to give you shock absorption, provide insulation when facing the elements, and gives you maximum support for carrying a heavy load. The quality of the Trekking Heavy Crew shines through as this sock maintains its density and cushion over time.
The socks are thick and toasty. An arch brace holds the Trekking Heavy Crew in place while providing extra support. Crew height means the sock reaches just over your calf.
Wear them while snorkeling in a dry suit. Count on them to support you on extended backpacking trips. The Trekking Heavy Crew can also be used to help you break in expensive boots without soreness. Ultimate impact absorption allows you to carry a heavy load and still feel strong on your feet - and comfortable.
These are an average price for Smartwool socks. Again, you won’t be disappointed with your investment as these socks have a lot of life in them.
- High wool content (70%)
- Super supportive for weight-bearing activity and intensive hiking
- All-season wear
- Maintains cushion & density over time
- Not quite as warm as the Mountaineering socks, may not be best for extreme cold
- May not work as well on athletic calves as performance fits do
PhD Run Light Elite Micro
Ultra light cushioning gives you the absolute least amount of bulk while still offering a suitable buffer between you and your foot. The thinness of this sock provides a barely-there feel while you’ll still get protection on the pressure points of your foot. You won’t have to adjust the size of your running shoe if you want to sport Run Light Elite Micro socks.
While the Run Light Elite Micro is available for both genders, the women’s version offers a distinguishing fit with a narrower sock body profile. These socks are made with 200 needle construction to supply the highest possible knit density while remaining incredibly lightweight. Micro socks are 1.5 inches in overall height, resting just below the ankle. Consumers report that this sock fits perfectly without being too tight, a boon for a micro running sock.
Mesh venting increases breathability while preventing moisture buildup. Keeping moisture at bay means this sock won’t slide around in your shoe when your foot sweats. As with the other PhD socks, the 4 Degree Elite Fit System keeps this sock in place throughout your activity. While most runners opt to use these socks in warmer weather, some reviewers have had extended success in single digit temps as well.
These socks are slightly less expensive than Smartwool’s hiking and mountaineering choices. It is a thinner, smaller sock however, so you may simply be paying less for less material. The new PhD line boasts even better quality than older Smartwool models, so you’re getting even more bang for your buck with increased product longevity.
- Perfect fit without being too tight
- Great for summer running
- Hold up excellently over time
- Soft feel
- Indestructawool technology
- Some users report that elastic around the ankle wears out after several washings so the socks slip down more easily
Hiking Medium Crew
Medium cushion buffers impact on the trail while keeping your feet warm. These will hold up well for moderate backpacking activity and decently rugged trail hiking.
Elastic arch support and flat knit toe seem increase comfort and support. Crew height comes just over calf. Sock wearers claim this one is mighty comfortable!
The Hike Medium Crew socks are perfect for medium impact hikes. These three-season, all-terrain socks will carry you solidly through the year barring the coldest of winter days and the most blistering summer days.
These host a fairly average price for Smartwool socks. While you won’t get the newer PhD technology features, these socks are valuable due to their three-season use and warmth without extreme bulk.
- Three-season, all-terrain
- Hold their shape
- Super comfortable
- Not very breathable
- Questionable durability
PhD Outdoor Ultra Light Mini
These socks feature ultra light cushioning. It doesn’t get lighter than this! These tough but thin multi-sport socks give you ultimate performance inside snug shoes. Thin padding means you’ll want to layer them for extended hikes, added warmth, or intense activity.
The Mini offers 3.75 inches in total height and fits snugly on your foot. The women’s version features a women’s distinguishing fit with a slender body profile and skinnier heel than the men’s sock. The PhD crossed elastic fit system maximizes flexibility while bolstering recovery and keeping your sock put.
Mesh venting optimizes breathability and keeps moisture in check. Th PhD Outdoor Ultra Light Mini will keep you dry while helping your feet regulate temperature. They’re a great choice for a variety of sports activity. These socks are noted to hold up particularly well over time, showing little to no signs of wear after many uses.
These socks are slightly less expensive than average for the Smartwool brand. Keep in mind that these are thin socks, so there’s less actual material in the sock. You’re getting excellent value for a lightweight multi-sport sock, even if you do decide to add on another layer for extended activity.
- Doesn’t scrunch up
- Thin yet comfortable
- Great airflow/breathability
- Indestructawool technology
- Too thin to be worn alone for hiking, but could be layered
- Not the warmest choice on its own
Hike Liner Crew
The Hike Liner Crew offers essentially no cushioning, but rather serves as an important base layer in your hiking getup. This lightweight sock is meant to be your second skin and helps to minimize friction and blisters.
You’ll benefit from the ultra comfortable flat knit toe seem. Crew height comes just over the calf, allowing you to match this sock well with other crew Smartwool hiking socks. This is a lightweight, cozy sock with superior fit.
Experience the moisture wicking properties of merino wool while experiencing added comfort and protection when you choose the Hike Liner as your base sock layer. These can be enough to wear as a lightweight hiking sock on warmer days. During non-sport activity, these socks can keep you warm and dry without the bulk of a typical wool sock.
These liners cost the least out of all the socks in this guide. The value is exquisite as you can purchase these affordable crew liners and experience the benefits of wool without bulk and with the ability to easily layer with other hiking socks of your choice. Win-win!
- Gives the benefits of a wool sock without the bulk
- Keeps feet from chafing
- Designed for layering, this sock is too thin to be worn alone for most activities
Hunt Extra Heavy Over the Calf
These socks are extra thick for maximum warmth and protection. You will want to ensure you have enough room in your boots for these bad boys. Heavy cushioning supplies heavy impact absorption.
These are taller than most crew socks to fit well in taller boots such as your hunting boots. Flat knit toe seam keeps toes comfy while ankle and arch braces hold the sock in place.
These socks have been reported to keep feet warm in temps as low as -60 degrees Fahrenheit when combined with a liner sock. The Hunt Extra Heavy is known for its superior wicking properties and high endurance. These socks are designed to keep you warm and supported over long periods of outdoor activity.
These are a little pricier than average for Smartwool socks, but the value shines with exceptional wicking and warmth. Plus, these are thick socks with a higher wool content (71%) than many of the others.
- Superior wicking
- Extra thick = extra warm and supportive
- High quality, endurance, performance
- Can compress when being worn for extended periods
Hiking Light Crew
Light half-cushion supports low-impact to moderate activity. Padding is uniform throughout the sock, maximizing impact absorption. Thinner construction and knitting also means increased breathability.
Elastic arch brace offers support and comfort. Flat knit toe seam keeps your toes comfy and protected. These socks stay put. Crew height comes just over the calf. Best of all the fit is long-lasting.
These socks work best for light to moderate-impact activity. Some opt to wear them as light trail socks, though you’ll probably want another layer in the winter or for intense activity. You can count on these socks to keep you dry and smelling good. These socks are a good choice if you’re looking for a daily wool sock that will keep you warm but won’t roast you in hotter climates.
While the Hiking Light Crew has an average price for a Smartwool sock, we think the value is a little bit less than that of the other socks on this list due to two main factors: the durability isn’t quite as great and the fit loosens over time.
- Great light trail socks
- Good breathability
- Keep their shape over time
- Comfortable choice for daily life off the trail, too
- Fit is a bit looser than the more modern PhD versions
- Not the most durable choice
The Criteria We Used for Our Evaluation of the Best Smartwool Socks
Here’s a deeper look at how we selected the best Smartwool socks for this guide.
How thick or thin is your sock, and what does this level of support mean? Some of these socks have extra cushioning in certain harder hit places like under your toe pad and heels, while other socks have uniform cushioning throughout. Socks with variable cushioning might work best for running and other dynamic activity while an all-encompassing thick cushioning could be ideal for an intense, long, or rugged hike or backpacking trip. Super thick cushioning is also going to give you the best support for weight-bearing activity.
When picking out your socks, it’s essential to know what level of cushioning you’re looking for and where you want it. All of these socks have effective cushioning design and serve their intended purpose well.
Cushioning also determines the amount of impact you can expect to handle while wearing the sock. If you’re looking for heavy impact absorption that you’d want for trekking seriously rugged trails for long miles while carrying a heavy load, go for thick cushioning. If you just want a minimal layer of protection between you and your sure, such as you might want for a light run or for an ordinary day of office work, opt for a lighter cushioning.
The fit metric refers to how the sock feels, the sock height, and how well the sock stays put. We’ve detailed specific support features and discussed what type of shoe or boot works best with each sock height. Some of these socks offer a women-specific fit which means the body of the sock and the heel are more narrow than the men’s version. We’ve also made sure to mention how well the crew-height socks work for athletic calves.
Some people prefer a tighter fit in their running socks. We’ve also highlighted any areas where users notice a progressively looser or tighter fit over time. Sometimes the elastic in the top of the sock wears out over time, leading to a sock that might fall down. And sometimes a running sock feels more tight as your feet sweat and swell during a run. Some users report certain socks feel too tight in very specific areas such as the ankle. If this is typically a problem area for you, that certain sock might not be the best choice.
All of the socks on our list rated exceptionally high for comfort and non-itchiness, essential values for wool socks.
When looking for the best sock for you, it’s essential to consider what type of climate you’ll wear them in and through what type of activity. Some of these are meant for warmer climates, some for cold, and others are multi-season. Some of these socks can support you to carry a lot of weight or help you handle an extreme run. We’ve made sure to describe what kind of activity, weather, and terrain these socks can handle
All of the socks on this list measure up well for wicking moisture and breathability, important qualities to prevent stinkiness and maintain comfort.
Smartwool socks are more expensive than average socks, and this is because they are not average socks! Smartwool socks offer exceptional quality, performance, and endurance. We’ve discussed how each sock measures up in the Smartwool sock price range, and what you’re getting for your investment.
Each sock on this list offers something unique and highly valuable for its price. Every sock here is a win.
Two additional factors to consider when determining the best Smartwool sock for you are the wool content of the sock and sizing.
Each Smartwool sock contains a unique Merino wool content typically ranging from just under 50% to over 70%. You’ll tend to find the warmer socks and hiking socks to have more wool content, while thinner and performance fit socks from the PhD line have less wool. Smartwool blends Merino wool with varying quantities of synthetic fibers to produce certain ranges of flexibility and support. You can easily find the wool content listed in the product description. Extra heavy socks tend to have the most wool while ultra light socks contain the least.
Smartwool socks seem to vary in running small or large, or fitting exactly. It helps to do some research of reviews ahead of time, which you can find online and even on the Smartwool website. If you don’t find the perfect fit the first time, you can always exchange your socks under Smartwool’s two-year warranty. Remember to properly care for your socks to keep them the right size (see our FAQ for care guidelines).
Q: How do I best care for my Smartwool socks?
A: This is a great question. Though some people value the option to always toss their socks in the dryer, we strongly recommend exclusively air drying your Smartwool socks for optimal product longevity. The manufacturer recommends machine washing on the gentle cycle in warm or cool water, socks inside out. Use mild soap, no bleach or fabric softener. You can tumble dry on a low setting, but never on medium or high as heat can shrink wool. Do NOT iron or dry clean your Smartwool socks.
Q: How often do I need to wash my Smartwool socks?
A: One of the best parts about opting for wool clothing over other clothing made from other fibers is that it doesn’t need to get laundered as often. Why? Wool does not hold on to stinky aromas. So sometimes you might just need to air out your socks or gently spot clean them. You can wear them several times before tossing them in the washer!
Keep in mind that some Smartwool socks have lower amounts of wool than others. These ones might need to be washed more often than high wool content socks.
Q: Is air drying a good option for Smartwool socks?
A: It is, and it may be a way to increase product longevity as drying your clothes the conventional route does pull fibers away over time. Just look in your lint trap to verify this tidbit! The manufacturer recommends laying your wool clothes flat as opposed to hanging them to dry. This is because wet wool changes shape while hanging. If your socks change shape in a way you’re displeased with, gently re-shape them while they are damp.
Q: What’s the best way to store my woolly socks during off-season? I don’t want moths to eat holes in them!
A: Well, we don’t want that either! Smartwool has provided a few easy steps to ensure secure storage of wool socks and clothing:
- Thoroughly clean your wool items. Moths dig the lingering odors from our bodies and food that remain in socks after wearing them.
- Keep your socks laying flat. Do not roll them up. Contorting their shape in storage can alter the sock’s shape
- Plastic bags and boxes are a great storage option for eliminating breathability, allowing your clothes to stay mold-free. If you find you keep your wool packed for a year or longer, make sure you air it out for some time before packing it up again.
- Stash cedar in your storage to ward off moths and other critters who might nibble at your clothes.
Q: What if I get a hole in my Smartwool sock?
A: It happens to the best of us, and to the best of socks, especially the more we love them and wear them out. If you get a hole in your Smartwool sock within its first two years and you’re feeling unsatisfied about it, exchange it under the warranty. If you want to repair the sock yourself, you can try darning the sock. Darning is a simple process of weaving wool yarn over any thin areas or holes in the sock. You can use a light bulb or a darning egg to place your sock over while making the repairs. Just make sure you try to match the weight of the yarn to the weight of the wool in your sock, if possible. There are plenty of great articles and videos on the web offering guidance on darning wool.
Q: Why choose wool?
A: If you’re not already convinced, think about this: wool is more breathable and keeps moisture at bay better than other fiber out there, especially the synthetic ones. When you aren’t trapping moisture in your socks, smelly bacteria don’t stand a chance at surviving. So you won’t stink.
Wool is sheep hair, and hair is made mostly from interlocking protein molecules. These keratin molecules give each wool fiber flexibility and incredible stretch in all directions, without causing breakage. These are seriously tough fibers! Tough yet flexible is just another magic mark of Merino wool.