Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (2023)

Are you planning to do some worthwhile outdoor adventures but stuck on choosing between Smartwool 150 vs. 250? Well, you don’t really need to get confused. It’s actually easy to pick between the two of them as long as you consider certain factors and considerations to use them.

In this review, we will be discussing the differences between Smartwool 150 vs. 250 (sometimes also called Merino 150 and Merino 250). You will also learn about the features and advantages of Merino Wool.

Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (1)

What is Merino Wool and Its Features and Advantages?

Smartwool 150 vs. 250

Merino Smartwool 150

Features, Advantages, and Usage

Enhanced Durability

(Video) Smartwool Shirts Reviewed :: Phd 250 & Nts 150

Acts as Heating Mechanism

Product range

Our Opinion

Merino Smartwool 250

Features, Advantages, Usage

Product Range

Our Opinion

Importance of Layering of Clothes

Choosing the Right Base Layers for the Weather

Smartwool Company

(Video) Men's Merino 150 Base Layer Long Sleeve by Smartwool [Review]

The Wool of Merino Sheep In the Eyes of Smartwool

Designing from the Inside Out


If you’re planning to buy clothing or products that are crafted with either Merino 150 or 250, you’ll love this guide.

With that said, let’s dive right in!

What is Merino Wool and Its Features and Advantages?

Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (2)

Merino wool is famous for its excellent properties, such as exceptional breathability, shine, and softness. Produced from the wool of Merino Sheep, ‘its fibers are more sensitive, finer, softer compared to other fabrics out there.

Common wool types are naturally insulating, water repellent, durable, and warm. All these properties, plus the exceptional qualities of this type of wool, add up to produce top-notch products.

In spite of a variation in grades among this kind of wool, it’s diameter is constantly microscopic, which ranges from 11.5 microns to around 24 microns. Merino Sheep are products of selective breeding, which explains why they can produce ultrafine, high-quality wool.

So, what are the advantages of Merino Wool?

  • Incredibly comfortable
  • Durable and long-lasting
  • It’s fire-resistant
  • Helps provide UPF Protection
  • It’s biodegradable
  • Ultrafine and soft
  • Perfect for traveling and longer treks
  • Absorbs odor caused by bacteria
  • It helps keep you dry and sweat-free
  • Helps regulate body temperature

These are some of the advantages of this kind of wool. Now, to further learn about this type of wool, let’s examine Merino 150 versus Merino 250.

Smartwool 150 vs. 250

Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (3)

Merino 150 means that the product has 150g/m2 of Merino Wool. Such products with these values are meant to be utilized as the base layer instead of outerwear. In particular, 150 is pretty comfortable to wear directly against your skin.

On the other hand, the Smartwool 250 means the product has 250g/m2 of Merino Wool. Relatively, 250 is a bit more versatile compared to 150 since it is not particularly designed to function as the base layer. Smartwool 250 is perfect if you’re dealing with harsh cold weather and looking for more insulation.

The Merino 150 is typically used for base layers of clothing and is commonly designed to get rid of moisture from the user’s skin. Meanwhile, 250 usually acts as the second layer.

Merino Smartwool 150

Merino 150 is your layer for everything. It is a lightweight collection of Merino wool apparel that is ideal for four-season layering and, of course, for everyday coziness.

Furthermore, Merino 150 is available in a variety of designs and fits while also providing optimal versatility. From Smartwool’s comfortable underwear to their stylish and lightweight hoodies, the Merino 150 transcends seasonality that can be worn in warm weather or integrated with other base layers in cold conditions.

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Features, Advantages, and Usage

Enhanced Durability

The Merino 150 has enhanced durability because it is crafted using Core Spun Technology, on which the Merino fibers are wrapped around a nylon core.

A nylon core is usually added to the wool base to enhance its strength while having minimal impact on the fabric’s insulation. However, keep in mind that the nylon core is not an insulating fabric. This is the reason why it is reserved as part of the apparel’s outer part.

The Merino 150 is crafted for year-round base layers to work with your body’s natural heating and cooling capabilities.

Acts as Heating Mechanism

The Smartwool 150 is usually used directly against the skin. It works with your body temperature to help with the cooling and heating processes. With 150, you are ensured that your core temperature stays at the optimal level.

Merino wool is a popular material for climbing and hiking. One good example is socks that are made from the wool of Merino. It prevents odor and moisture from accumulating on your feet.

Typically, the Merino Smartwool 150 serves as a fabric for mild weather base casual, bottom, and layer tops. Merino wool is also used to craft accessories.

Product range

Usually, clothing crafted with Merino Smartwool 150 fabric are hoodies, base layer tops, base layer bottom, and cold-weather accessories such as gloves. Here are some cool examples:

Our Opinion

The Smartwool 150 is perfect for casual layering during cold months. However, if you can’t handle the cold, the Smartwool 250 can provide additional warmth. Also, the Smartwool 250 provides better protection for preventing frostbite.

Merino Smartwool 250

Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (4)

The collection of Merino wool products and base layers are perfect for cold-weather outdoor activities where breathability and warmth are essential. Merino 250 can effectively eliminate moisture away from the user’s skin while it is still in a vapor state, which ultimately helps keep you odor-free, dry, and warm all day long.

Even though Merino 250 is breathable, it is not ideal for intense physical activities because it has heavier and thicker material than Merino 150.

Features, Advantages, Usage

The Merino Smartwool 250 is perfect to use as a base layer, especially for cold environments. The Merino 250 also serves as the second piece of the layering system in many clothing.

Smartwool 250’s manufacturers concentrate on designing the cloth breathable and warm. Even though it’s not breathable compared to 150, the Smartwool 250 still feels incredibly soft.

The wool is crafted with an interlock knit, which makes it perfect for warmth without the bulk. Additionally, this aids the fabric to resist odors easily.

Product Range

Similar to 150, clothing crafted with 100% Merino Smartwool 250 fabric are usually hoodies, base layer tops, base layer bottom, and cold-weather accessories – which include gloves and beanies. Here are some cool examples:

Our Opinion

We all know now that Merino wool is one of the best fabrics to keep your body warm and dry, particularly in cold weather. Smartwool Merino 250 comes with very simple construction, but it is still very effective, especially against cold settings. Unlike Merino 150, 250 has heavier and thicker material, which makes it suitable for colder environments.

Furthermore, 250 offers an impressive temperature regulation, which makes it breathable and cozy. It is one of the thickest types of wool offered by Smartwool. Also, since Merino 250 is composed of high-quality fabric and heavily crafted, expect it to be pricier.

Keep in mind that since the Merino Smartwool 250 is made with thick and absorbent material, it will also absorb some moisture in the air, which can add up to the heaviness of the clothing.

Importance of Layering of Clothes

Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (5)

(Video) Smartwool Merino 150 Boxer Briefs

If you want to prevent dangerous exposure and make the most out of your cold-weather clothing, then proper layering techniques can help you. The importance of layering clothes is that it protects you from freezing snow and cold air by maintaining your core body heat.

If you’re usually working in a cold storage facility or outside during cold months, then wearing three layers of clothes is essential. What you want to wear is a base layer for absorbing moisture away from your body, then a second layer for insulating your body from the cold environment, and the last layer that will serve as a barrier between you and the cold.

Choosing the Right Base Layers for the Weather

For the base layers, you would want to pick something that is made of wool, specifically Merino wool fabric. You probably want to choose something that is made of cotton because this material tends to trap moisture and become soggy.

And remember that the damper your clothes are, the more dangerous it is in cold weather. But with Merino wool’s exceptional absorption, you don’t need to worry about moisture in your clothes.

As for the second layer, it traps air close to your body to keep it warm. Merino wool is a great insulator, which makes it perfect for the job. Moreover, it is usually found in different weights to fit your needs so that you can be comfortable as much as possible.

The outer layer, on the other hand, is as good as armor. It effectively protects you from the cold of the winter weather. The outer layer is essential because when your base layers get damp, the outer layer maintains your core body temperature.

In particular, by opting for this type of wool, you make an escape route for excess heat and sweat to be released. Each layer of this wool works to transfer sweat away from your skin and redirect the sweat outside of your gear.

This is a hard task for synthetic layers because they just tend to block the escape route for sweat vapor you produce, which significantly increases your chances of getting clammy and cold.

Smartwool Company

Smartwool 150 vs. 250 Differences, Advantages & Buying Guide (6)

Established in 1994, Smartwool is a Private American Company founded by two ski instructors – Patty and Peter Duke.

In 2005, a company that manufactures and a retailer of outdoor wear – The Timberland Company – acquired Smartwool. Then in 2011, when the Timberland Company was acquired by VF Corporation, Smartwool became a subsidiary.

When it comes to manufacturing products using Merino Wool, Smartwool is one of the most popular companies out there. They are known for manufacturing anti-microbial and odor-reducing fabric.

They are also notable for establishing long-term partnerships with wool suppliers that are very strict when it comes to husbandry standards and ensuring animal well-being.

The Wool of Merino Sheep In the Eyes of Smartwool

According to the brand, the wool of Merino is quite exceptional. The material’s sustainable and natural fibers help boost adventures in many ways than the company could imagine when they started manufacturing socks over 20 years ago.

After they discovered that this type of wool was so beneficial in socks, the company started manufacturing Merino wool apparel for backcountry skiing to multi-week treks, and even for strenuous exercises. The company thinks that Merino wool apparels are perfect when it comes to staying cozy in the outdoors.

Designing from the Inside Out

The brand thinks that layers matter, especially base layers. Thus, they design it from the inside out. In other words, the company put Merino wool where it matters, which is next to the skin. They also concentrate on utilizing low-profile, non-chafing, and strategically placed seams in order to provide users optimal comfort.

Furthermore, Smartwool focuses on end-use comfort and performance for its customers. This way of manufacturing helps consumers to stay focused on every powder turn, summit, and lap.


Unlike many other types of materials, the wool of Merino is much pricier. However, when it comes to fabric that can effectively prevent odors and has great temperature regulation, it is a perfect choice. Clothing made from Merino wool is simply worth the price.

All in all, Merino wool is a material that is essentially very soft, cozy, comfortable, and it stays dry on the user’s skin. Now that we know how good of a material Merino wool is, it’s just now a matter of choosing apparel that is made from either Smartwool 150 or Smartwool 250.

If you like this review, please leave your feedback in the comment section below. Thank you, and we hope to see you in another review!

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What is the difference between Merino 150 and 250? ›

Their merino wool is always comfy, moisture-wicking, and keeps you warm at its intended temperature range. That said, any Smartwool 150 will be extra breathable just because of how thin the fabric is. And compensating for its decreased breathability, the 250 layers will be significantly warmer.

What does 250 mean in Smartwool? ›

Smartwool is moving away from the 150 and 250 labels, which indicated the weight of merino in the garment in grams, i.e., 150g or 250g.

Is Merino 250 the warmest? ›

They're 100% Merino wool, some of the best wool available. They aren't warmer than other wool garments with the same fabric density. But, no 100% merino wool 250-weight garments will be warmer than other 250-weight clothing unless they're thicker.

Is Smartwool classic the same as 250? ›

Smartwool has rebranded the Merino 250 Crew to the Classic Thermal. The shirts use the same material, but the Classic Thermal version has a new fit and some different seamlines. Note that online stores may still be selling either version.

What percentage of merino wool is best? ›

I primarily looked for socks woven with at least 40 percent merino wool, which has fine, non-itchy fibers with natural odor resistance. Crucially, these fibers can absorb a lot of water before the wearer experiences any discomfort or cold.

What does merino 150 mean? ›

Merino 150 means there are 150 grams of merino wool for every square metre of fabric. (If you suffer from the cold you'll want more wool per square metre.)

How do you clean a merino 250? ›

Machine-wash on gentle cycle in warm or cool water (avoid hot water as heat may shrink wool). Use mild soap, no bleach or fabric softener (bleach destroys the Merino wool fibers, and fabric softener coats those fibers—reducing their ability to naturally manage moisture and regulate body temperature).

What is a good percentage of wool? ›

You can expect to invest $200-400 on a good coat with at least 60% wool content.

How do you choose the best merino wool? ›

Shop By Thickness / Weight

The weight of the fabric is measured in microns, and the lower the number, the finer the wool. Superfine merino wool has a micron count of 17.0 or less, while superfine merino wool has a micron count of 19.0 or less.

What is the best base layer for extreme cold? ›

Merino wool is the ideal base layer fabric, as the organic fabric is safe for your skin, naturally anti-microbial, and ridiculously comfortable! Smartwool is the leading brand for merino wool performance clothing, and their base layers are the perfect centerpiece of any cold weather outfit!

Are there different grades of merino wool? ›

Merino wool yarn is finer so it's softer. It's also low allergenic which definitely helps keep it soft against skin. So no, Merino wool doesn't itch. Be aware that whilst the label may state 100% merino there are many different grades of merino, spun thicker & thinner and knitted to different specifications.

What is the difference between merino wool and Smartwool? ›

Smartwool uses denser merino wool in its clothing. Meriwool relies on different thread materials, which makes its clothing not as warm and slightly itchier. To some people, those initial few weeks of merino wool becoming less itchy are a big deal.

Should I size up or down in Smartwool socks? ›

Do Smartwool socks run big, small, or true to size? Smartwool socks run true to size, based on your total foot length (and calf circumference, for compression socks).

Why are my Smartwool socks Pilling? ›

Pilling is caused by the way yarn is made. In a yarn numerous wool fibers are spun together in a long thread. Washing and wearing a wool garment can cause loose fibers to push out from the surface and form into a small ball or pill. Friction is the main factor in causing pilling.

Does Smartwool shrink in dryer? ›

They are washed in cold water and air dried in the dryer. I have not noticed any shrinking. My Smartwool shirts and socks are treated the same way, and also have shown no signs of shrinking. I use the socks every day, year round.

What is a disadvantage of using merino wool? ›

Even though Merino is a fantastic temperature-managing fabric, it tends to be delicate. Much of the ultralight apparel (140 – 180 GSM) is especially weak since it is thin. And, with excessive use and over-washing, holes can sometimes form.

What are the disadvantages of merino sheep? ›

They are thin and "slabby" with softer skin and more folds and wrinkles than other breeds. They grow more slowly and succumb to weather more easily. They're harder to shear and have a reputation for getting footrot, though that's not a major problem for the Thompsons' flock.

How often should you wash merino wool? ›

Merino wool's beauty is that its odor-resistant properties mean you don't have to do laundry as much. Most companies suggest you wash their garments after about 3-20 wear cycles.

Is 100% merino wool best? ›

One of the reasons that merino wool is so popular is its warmth relative to weight. The fabric has a natural loft that traps heat very efficiently between the fibers, making it warmer than a synthetic of the same weight. But it's also good in the heat, as merino regulates your body temperature really well.

Is 100% merino wool itchy? ›

Merino wool is able to ditch the itch thanks to its fiber's smaller diameter, or being “finer”. These fibers are more flexible and softly bend when pressed against the skin and, therefore, don't itch like other wool.

What do the numbers mean in merino wool? ›

Counts range from 36s to 80s. The higher the number, the thinner the fiber. For example, Merino wool has a high count (64–80) and Lincoln wool has a low count (36–46).

What is best grade of merino wool? ›

Ultrafine Merino

Ultrafine wool is the finest wool in the world, and it has a micron range of 16.1 to 17.5.


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