Coolmax vs Merino Wool for Summer Hiking (Socks)

Wearing the wrong kind of socks during your summertime adventures in the backcountry is guaranteed to leave you with sweaty, stinky feet.

To avoid this, one needs to purchase a pair of socks made out of material that is suitable for warm-weather trekking. Both Coolmax and Merino wool can be a good choice in this regard.

This is because both of these fabrics have excellent moisture-wicking properties, and they also feel very soft and comfortable.

However, there are still some differences between them – unlike Merino wool, which is a natural material by itself, Coolmax is a synthetic fabric. Also, when compared to Coolmax socks, the socks made out of Merino wool are significantly better at dealing with odors.

In this Coolmax vs Merino Wool comparison, I’ll compare these two materials in a couple of different departments and try to help you decide which one of them you should go with.

Features of Coolmax Socks

Thermoregulating hiking socks

Smooth & Soft

Due to the polyester materials used in their manufacture, Coolmax socks are always smooth and soft. By design, these kinds of socks have a higher surface area, which doesn’t only make them exceptionally comfortable but also allows them to dry quite quickly.

Excellent for All Temperatures

A lot of people choose to go with synthetic socks instead of wool ones because they’re capable of pulling the sweat away from the skin. In addition, they are quite breathable.

The moisture-wicking properties and the overall breathability of Coolmax allow socks made out of this material to quickly dry out one’s feet. This results in warmer feet in the winter and cooler feet in the summer.

Features of Merino Wool Socks

Hiker wears merino wool socks


Due to the fact that the wool sourced from Merino sheep is hair-like, Merino wool socks have multiple layers of fabric within them. These trap the odor-causing bacteria and reduce the overall amount of odor being “emitted” from the socks.

In other words, the chances of having stinky feet while wearing Merino wool socks are much smaller than while wearing regular socks.


One thing that Merino wool is well-known for is its ability to wick away moisture.

The main culprit behind Merino wool’s moisture-wicking properties is the skinny fiber that comes from Merino sheep, whose permeability allows sweat to move away from one’s feet and end up in the sock’s fibrous layers.

Do know that some socks with a Merino Wool lining are even waterproof. Check out my reviews of the best waterproof socks.

Similarities Between Coolmax and Merino Wool Socks

Close up hiking socks

The most notable out of all properties shared by Coolmax and Merino wool is their moisture-wicking ability. In other words, both of these types of socks are capable of keeping one’s feet dry by pulling the sweat away from them. They can also reduce chafing.

Furthermore, both types of socks are often well-cushioned and therefore very comfortable.

However, an important thing to mention here is that Coolmax socks aren’t exactly as thick as the Merino wool ones are, which means that they don’t offer as much protection.

But still, both Coolmax and Merino wool socks are very protective and will keep your feet safe from rubbing and blisters. Nevertheless, it might be a good idea to get sock liners as well in order to prevent blisters.

Both Coolmax and Merino wool socks can be purchased in most sportswear stores. What is more, sometimes these two materials are blended together, with the result being a pair of socks which has the benefits of both fabrics.

But still, most people choose to go with only one type of socks in order to avoid the drawbacks of the other type.

Does Merino Wool Shrink?

This is a question posed by many people who can’t decide whether to go with Coolmax or Merino wool socks. Unfortunately, yes – when it’s exposed to high temperatures, this material does shrink.

However, there’s an easy way to prevent this from happening. To prevent your Merino wool socks – or any other clothing made out of this material – from shrinking, make sure to machine-wash them in cool or slightly warm water. This should then be followed by low-setting tumble-drying or air-drying.

Differences Between Coolmax and Merino Wool Socks


Woman puts on hiking socks

Obviously, the biggest difference between these socks is that they’re made out of different materials.

As I’ve already mentioned, Merino wool socks are made out of a natural material – the wool obtained from Merino sheep. It goes without saying, but when compared to Coolmax, Merino wool is undoubtedly a better choice if you care about the environment, as this material is biodegradable.

Typically, a Merino sheep is shaved around five times throughout the year. In other words, you can get a lot of wool from just one sheep. Furthermore, obtaining Merino wool doesn’t require as much fossil fuel as manufacturing Coolmax does.

As I’ve already mentioned, Merino wool is highly porous and fibrous. The result of this is Merino wool’s stunning ability to keep the moisture at bay while keeping your feet super cool/warm at the same time.

Coolmax, on the other hand, is made out of polyester and is, therefore, a synthetic material. While this turns it into a not-so-sustainable choice, Coolmax feels exceptionally comfortable on the skin and is also the only viable choice between the two materials if you’re allergic to wool.

While it’s true that Coolmax dries quite quickly, it does not provide as much warmth as its rival. While the wool stimulates one’s body to rewarm the wet area of the skin, the polyester material such as Coolmax just dries.

Another thing worth mentioning here is that some brands that manufacture synthetic socks use recycled polyester. That’s something to keep in mind if you decide to go with Coolmax.

Also, Coolmax socks cannot be manufactured without the use of formaldehyde. So, even if they’re made with eco-friendly practices, these kinds of socks still contain some harmful chemicals.


Hiker wearing trekking socks

During my years of hiking, I have used both Merino wool and Coolmax hiking socks, and I can safely say that both options feel very comfortable. There’s not much difference between these materials in the department of comfort.

However, if I would have to choose between these two fabrics, I would probably go with Merino wool. I like how socks made out of this material feel on my skin, and I also like the cushioning they provide.

Furthermore, these kinds of socks tend to be cozier in a wider array of temperatures. The Coolmax ones, on the other hand, tend to be either too cold or too hot to wear in different situations, forcing you to carry multiple pairs.


Hiking socks and boots

Both Merino wool and Coolmax socks are designed to keep bad odors at bay. The Merino wool fibers, for example, trap the odor-causing bacteria but also wick away the sweat.

Coolmax socks, on the other hand, are very breathable and that certainly helps them to deal with odors and moisture. However, over the years, I realized that these socks hold onto scents for longer than their wool-made counterparts.

From personal experience, I can tell that the socks made out of Merino wool have successfully kept my feet fresh and cool after many 10-mile hikes in the wild – there were no bad odors at all.

What is more, I was always able to wash them in creeks, without any soap. And every time I did that, I would simply hang them on my backpack and they’d be completely dry by the day’s end.

But I have to point out that Coolmax socks have an important advantage over the Merino wool ones – they dry faster.

As you already know, wool is not the quickest-drying material, so even though your Merino wool socks may be capable of wicking the sweat away from your feet, they will still hold onto it for a longer period of time than the Coolmax socks.


Most Coolmax socks will run you anywhere between $15 and $25. The Merino wool socks, on the other hand, are usually in the $15 – $30 price range. In other words, the prices between them are quite comparable.

Those who want to buy a pair of genuinely well-made trekking socks have to fork out at least $20 per pair. Investing in a pair of quality socks is undoubtedly a worthwhile endeavor for anyone who is serious about hiking.

The Verdict

Yellow merino wool socks

So, which type of socks is better for summer hiking? Coolmax or Merino wool?

Personally, I consider the Merino wool ones to be a better option – they are longer-lasting and more versatile, as they can keep one’s feet super warm during wintertime hikes. Moreover, they tend to stay more comfortable throughout the whole day, i.e. during hot afternoons and cold mornings.

However, Coolmax socks are undoubtedly a better option for all those who value fast-drying over flexibility and temperature. So, in the end, it all boils down to your personal preferences and needs.

Don’t forget that you can also combine the two. A lot of trekkers wear Coolmax socks on the inside, where they wick away the sweat while staying dry, and Merino wool socks on the outside, where they provide thermoregulation and cushioning.

Now that you know which socks to get, you may want to figure out what are the best hiking shoes for you.

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