Merino Wool vs Polyester – Which is Better?

Choosing between Merino Wool vs Polyester can be a source of debate on which material is better.

Comparing polyester vs merino wool: who wins?


Based on activities

There’s little to no doubt that wearing wool probably isn’t a great idea for a jog. Merino wool does a great job handling moisture up to a point, then it’s soaked. Polyester on the other hand is much more performative for wicking large amounts of moisture fast. And when it gets soaked, it’s lighter.

On the flip side, Merino excels for handling colder temperatures and wicking gradual moisture. That’s why it is a great choice for a hiking sock like I covered in my Smartwool hiking socks review. Polyester’s largest weakness as a base layer is that it won’t keep you as warm.

Merino sheep in a field

Socks aren’t the only ideal use for Merino wool while hiking, though. It also makes for great shirts due to the aforementioned properties as well as being anti-microbial. That means after some hard hiking, you won’t smell nearly as bad as you would in cotton or polyester.

Naturally, though, you wouldn’t want to wear merino in the summer, so polyester would win in that instance. Some wool shirts are surprisingly thin though, so this might be a closer comparison than you’d think. Be sure to check the thickness of any wool before buying, as that will help give you an idea of how warm it’ll be.

Winner: Tie

Based on Price

It should come as no surprise that polyester is much more affordable than Merino wool. That being said, as you go higher in quality the difference tends to drop. Natural materials like wool are almost always more expensive but are worth it.

For me, I tend to buy my wool gear on sale and infrequently to offset the cost. Because just like polyester, the higher quality stuff gets mindbogglingly pricey.

Winner: Polyester

Based on Comfort and Breathability – important qualities for fabric!

This is another completely one-sided category, and it’s all in favor of Merino wool. It’s soft, fuzzy, and just feels good. Polyester on the other hand is very light but tends to cling once it’s wet. If you’re going on an outdoor trip, there’s no doubt that wool is going to serve you better.

If you’re wondering if Merino wool is itchy, it’s not. It’s much more comfortable than that old wool sweater you had as a kid. The first time I got a pair of Merino wool socks years ago blew my mind. I’d never felt something so cushioned and soft on my feet before.

Winner: Merino wool

Based on Durability and Maintenance – Key for backpacking

Let’s be real here, we all want the minimum when it comes to taking care of our clothes. I want to wash them and not have to do anything else! When it comes to durability, I feel like I have to give the slight edge to polyester, but just barely. The tight stitching of the material and the synthetic nature of it makes it less likely to have issues.

And when you’d think it would be a runaway in favor of polyester for maintenance, that’s not necessarily true. Merino wool does require slightly different care, but not more. For example, to wash some wool clothing you’d want to wash them with a mild soap (no detergent or fabric softener.) Then, hang or set them out to dry. That’s not bad, and that’s coming from a guy that doesn’t enjoy doing laundry.

Merino wool also dries incredibly fast due to its natural properties. It’s not the slow process it might sound like.

Winner: Tie (Slight edge to polyester)

Based on Sustainability – Merino all the way?

It should come as no surprise that the natural material is much more sustainable (Merino wool.) The reason is that the process to create polyester (plastic fibers) relies on chemicals. It also ends up in the water supply over time due to microplastics.

Merino wool also doesn’t require as much washing as polyester, provided that it didn’t get much moisture. The ability to reduce washing actually helps sustainability a lot since it requires a lot of energy and water to do.

Even though it’s hard to avoid synthetic clothing altogether, it’s something I’m trying to do more of.

Winner: Merino wool

Merino wool vs polyester socks

For me, this entirely depends on the weather where I’m going. If it’s a day trip and sunny, polyester socks are the no brainer choice.

In almost any other condition, I personally will go with merino wool for it’s insulating and sweat wicking properties. It’s really incredible for a natural material.

In any case, you could always bring both types if you know that your trip is going to be long enough to justify it. No shame in being prepared! (Unless you’re doing some ultralight backpacking that is…)

Common question: Is polyester worse than wool?

Not necessarily. Like I mentioned above, they are both extremely dependent on the situation. Polyester is a great base layer in a lot of climates and is certainly more affordable.

As much as I would like to live in an ideal world where everything was organic and natural, reality can be much different! We’ve got to be practical with our choices based on what we can afford / sustainability / our own goals.

So which one is the overall winner?

As much as I would love to declare an overall winner, it’s not simple enough to do. Both of them excel in different activities, and it’s not uncommon to wear both at the same time. Polyester and other synthetic materials will almost always have a place in a wardrobe. Largely because of the price and performance you get with them. Polyester vs Merino wool largely depends on your needs for a trip.

A woman hiking with a backpack


If it were up to me, everyone would be wearing natural-based clothing that was sustainable. However, until it becomes more affordable to do so, we’ll have to compromise. Merino wool is a fantastic material that stands head and shoulders above regular wool. Just the fact that it can compete with something made in a lab is pretty outstanding!

I’m always expanding my wardrobe and picking up wool gear when I can. It’s not uncommon to find some killer deals at REI if you know when to go. I’m still rocking the last pair of Smartwool’s I got and they’re just as good as the day I bought them.

What are some of your favorite Merino wool and polyester gear that you’ve purchased? Let me know in the comments!

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