The Men's Merino 250 Base Layer Bottom from Smartwool is an upgraded version of Smartwool's Merino 250 Base Layer Bottom. This new version gives you an even better fit, thus giving you a pair of more functional underpants. The more technical advantages of 100% merino wool are that it both keeps you warm while you can be active without getting sweaty and damp. The underpants are ideal for skiing, running and hiking.
The Men's Merino 250 Base Layer Bottom from Smartwool is an upgraded version of Smartwool's Merino 250 Base Layer Bottom. This new version gives you an even better fit, thus giving you a pair of more functional underpants. The more technical advantages of 100% merino wool are that it both keeps you warm while you can be active without getting sweaty and damp. The underpants are ideal for skiing, running and hiking.
The Men's Merino 250 Base Layer Bottom from Smartwool is an upgraded version of Smartwool's Merino 250 Base Layer Bottom. This new version gives you an even better fit, thus giving you a pair of more functional underpants. The more technical advantages of 100% merino wool are that it both keeps you warm while you can be active without getting sweaty and damp. The underpants are ideal for skiing, running and hiking.
The Men's Merino 250 Base Layer Bottom from Smartwool is an upgraded version of Smartwool's Merino 250 Base Layer Bottom. This new version gives you an even better fit, thus giving you a pair of more functional underpants. The more technical advantages of 100% merino wool are that it both keeps you warm while you can be active without getting sweaty and damp. The underpants are ideal for skiing, running and hiking.
Last updated at 03/21/2026 15:52:55
Smartwool Merino 250 Base Layer Pants Black XL Boy SW0163620011.XL
Delivery $19.99
originally posted on altitude-sports.com
Having used Smartwool tops in the past for my base layers and beanies, I had an idea of what to expect on the 250 bottoms. But having used various polyester bottoms for years, I was pleasantly surprised by these as they feel an upgrade to the poly variants I have used.The Smartwool 250 bottom is a quality product, great fabric, stitching and finish. Performance is the curious part here. With poly bottoms I can go in various thicknesses to regulate warmth. Nice feature of that. However, thicker ones don't manage moisture as well, but ya they keep ya warm. The Smartwool Merino 250 bottoms stay pretty warm too in cold temps ( up to -13 for me), but regulate comfort better, as they breathe very well, are a great insulator and manage moisture better than my polyesters ... MoreHaving used Smartwool tops in the past for my base layers and beanies, I had an idea of what to expect on the 250 bottoms. But having used various polyester bottoms for years, I was pleasantly surprised by these as they feel an upgrade to the poly variants I have used.The Smartwool 250 bottom is a quality product, great fabric, stitching and finish. Performance is the curious part here. With poly bottoms I can go in various thicknesses to regulate warmth. Nice feature of that. However, thicker ones don't manage moisture as well, but ya they keep ya warm. The Smartwool Merino 250 bottoms stay pretty warm too in cold temps ( up to -13 for me), but regulate comfort better, as they breathe very well, are a great insulator and manage moisture better than my polyesters (mostly Under Armour models). These are comfortable (no itch and soft on skin), warm and quite noticeably stay 'fresher' longer before being in need of a wash.I have a ton of outdoor gear for winter hiking, as I do quite a bit of that. The Samrtwool 250 legs get my thumbs up and I can say I like them better for performance overall, than any of the UA polyesters I have. Plus Merino does well in warmer temps, so can't wait to try em in the Spring. If the durability is good on these, then I won't get Poly baselayer bottoms ever again.These frequently go on sale online, which is nice and is frequently discounted here, at Alti. But gonna throw a further two cents into shopping at Alti, for super quick shipping to Ontario, loyalty rewards and great return policies.
originally posted on smartwool.com
I bought these for those long walks to class on negative temp days here in northern new york. Since then, every time the temp even thinks of going negative I chuck these things on. They simply do the job. My legs stop feeling like their gonna fall off from the cold and my walks to class are way more comfortable. On top of that, their light enough to jog outside on warmer days with a pair of shorts over them. Overall, they do the job when it's cold, and don't overheat me when I get inside. If your on the fence and need something similar, pull the trigger brother! It's worth it! #sweepstakes
originally posted on smartwool.com
Having been a mail carrier in Seattle for the past 15 years, Smartwool products have become essential to my workwear wardrobe. Head to toe Smartwool is not uncommon during the cold months (uniform pieces over, of course). The only issue I've had is with the base layer bottoms. Holes have slowly formed in the crotch areas and eventually (1-2 years) I would toss the bottoms out. However, considering that the daily use included walking for miles and climbing stairs, the value was still there for me. Now with a driving centric delivery route, I anticipate that this 250 base layer bottom will last for several years. I'd experienced the aforementioned issue with other brand's comparable products. SW just has a better skin feel.
Smartwool Merino 250 Base Layer Pants Black XL Boy SW0163620011.XL
Delivery $19.99
Having used Smartwool tops in the past for my base layers and beanies, I had an idea of what to expect on the 250 bottoms. But having used various polyester bottoms for years, I was pleasantly surprised by these as they feel an upgrade to the poly variants I have used.The Smartwool 250 bottom is a quality product, great fabric, stitching and finish. Performance is the curious part here. With poly bottoms I can go in various thicknesses to regulate warmth. Nice feature of that. However, thicker ones don't manage moisture as well, but ya they keep ya warm. The Smartwool Merino 250 bottoms stay pretty warm too in cold temps ( up to -13 for me), but regulate comfort better, as they breathe very well, are a great insulator and manage moisture better than my polyesters ... MoreHaving used Smartwool tops in the past for my base layers and beanies, I had an idea of what to expect on the 250 bottoms. But having used various polyester bottoms for years, I was pleasantly surprised by these as they feel an upgrade to the poly variants I have used.The Smartwool 250 bottom is a quality product, great fabric, stitching and finish. Performance is the curious part here. With poly bottoms I can go in various thicknesses to regulate warmth. Nice feature of that. However, thicker ones don't manage moisture as well, but ya they keep ya warm. The Smartwool Merino 250 bottoms stay pretty warm too in cold temps ( up to -13 for me), but regulate comfort better, as they breathe very well, are a great insulator and manage moisture better than my polyesters (mostly Under Armour models). These are comfortable (no itch and soft on skin), warm and quite noticeably stay 'fresher' longer before being in need of a wash.I have a ton of outdoor gear for winter hiking, as I do quite a bit of that. The Samrtwool 250 legs get my thumbs up and I can say I like them better for performance overall, than any of the UA polyesters I have. Plus Merino does well in warmer temps, so can't wait to try em in the Spring. If the durability is good on these, then I won't get Poly baselayer bottoms ever again.These frequently go on sale online, which is nice and is frequently discounted here, at Alti. But gonna throw a further two cents into shopping at Alti, for super quick shipping to Ontario, loyalty rewards and great return policies.
I bought these for those long walks to class on negative temp days here in northern new york. Since then, every time the temp even thinks of going negative I chuck these things on. They simply do the job. My legs stop feeling like their gonna fall off from the cold and my walks to class are way more comfortable. On top of that, their light enough to jog outside on warmer days with a pair of shorts over them. Overall, they do the job when it's cold, and don't overheat me when I get inside. If your on the fence and need something similar, pull the trigger brother! It's worth it! #sweepstakes
Having been a mail carrier in Seattle for the past 15 years, Smartwool products have become essential to my workwear wardrobe. Head to toe Smartwool is not uncommon during the cold months (uniform pieces over, of course). The only issue I've had is with the base layer bottoms. Holes have slowly formed in the crotch areas and eventually (1-2 years) I would toss the bottoms out. However, considering that the daily use included walking for miles and climbing stairs, the value was still there for me. Now with a driving centric delivery route, I anticipate that this 250 base layer bottom will last for several years. I'd experienced the aforementioned issue with other brand's comparable products. SW just has a better skin feel.
I recently reviewed the 1/4 zip 250 baselayer top. Ditto everything I said for these bottoms. Warmth is only their secondary benefit in my opinion. It's the odor control of merino that's really awesome. I rarely need to wash it. I wear them multiple times with no issues. Recently wore them biking to work. I was able to bike home, hang them up for an hour or two then put them back on to go for an evening walk with my wife. These are wonderful.My only complaint would be that they are short for me. I am 6'6" with a 36" inseam and these are more like capris on me. That was expected since I rarely ever find anything long enough. I just wear longer socks to cover any exposed leg.
Well i’m still SUPER happy about my purchase however I really needed the L, however, it “disappeared”, so I bought the XL in its place… I will take in the seat, and the waist instead…. You can’t win them all I guess, but it’s all ok…,Completely thrilled with the Smartwool base layer…. I purchased the long sleeve top last year from Altitude Sports, and It’s, wash wear, wash wear, and repeat……! ! ! I live in it, and the $10 credit will go towards my 3rd Smartwool piece very soon…. Thank You very much, Altitude Sports…,,! ! ! Darren Cross
Love this. Been searching for new base layers for some time and smartwool's wool is all time. Way better then others I've tried.Soft, stretchy, warm, comfortable odor resistant and colors to match their tops. Underrated feature is the fly access, I can't stand being bundled up in ski gear and having to figure out how relieve myself outside.I'm also looking forward to use them to sleep outdoors while camping.I'm a huge fan of these.
Bought these for my father who has worn Smartwool base layers for many years. He has always worn size Medium in Smartwool but these were tighter not only around the legs, but around the waist as well. And he is even a slim person. It was like they ran a full size smaller. I always wear size small, so I tried them on and the medium actually fit me well; only slightly long in length. Seems like Smartwool changed the fit to make the base layers tighter and more compression-like. While this may work for certain types of winter sports and young customers who wear their pants tight these days, it is not a comfortable fit for your average consumers to simply wear all day. The fit is too restricting. I wish they would bring back the older, slightly more relaxed fit so my ... MoreBought these for my father who has worn Smartwool base layers for many years. He has always worn size Medium in Smartwool but these were tighter not only around the legs, but around the waist as well. And he is even a slim person. It was like they ran a full size smaller. I always wear size small, so I tried them on and the medium actually fit me well; only slightly long in length. Seems like Smartwool changed the fit to make the base layers tighter and more compression-like. While this may work for certain types of winter sports and young customers who wear their pants tight these days, it is not a comfortable fit for your average consumers to simply wear all day. The fit is too restricting. I wish they would bring back the older, slightly more relaxed fit so my father can continue buying Smartwool.
When doing my research on this product, I saw a regular thread of one criticism arise for Smartwool products: the Merino 250 and 150 baselayers, in general, are not very durable. However, I thought that maybe those people with those complaints used their products more vigorously or for more demanding activities than I intended. My intended use for these products was simply for every day, around town, office, and home activities when outside temperatures dropped below 30 degrees (i.e. not camping, hiking, cycling, mountain climbing, etc.). I decided to give the 250 baselayers a chance and try out for myself. I bought a top and a bottom in preparation for the winter, but before committing to buying more Smartwool products, I wanted to test the durability for myself. ... MoreWhen doing my research on this product, I saw a regular thread of one criticism arise for Smartwool products: the Merino 250 and 150 baselayers, in general, are not very durable. However, I thought that maybe those people with those complaints used their products more vigorously or for more demanding activities than I intended. My intended use for these products was simply for every day, around town, office, and home activities when outside temperatures dropped below 30 degrees (i.e. not camping, hiking, cycling, mountain climbing, etc.). I decided to give the 250 baselayers a chance and try out for myself. I bought a top and a bottom in preparation for the winter, but before committing to buying more Smartwool products, I wanted to test the durability for myself. Well, I used these products for my intended use-case, and here are a few of my experiences:1) I can confirm that these are not very durable. I owned them for 12 weeks in total. I used them for about 25 days in total, and I washed them 5 times in a machine wash gentle, as well as 1 time by hand. The first time I hung these to dry, they needed 5+ hours to dry. So, afterwards, I would throw these in the drier on low for about 10 minutes, and then I would hang them to dry. This sped up the amount of time to hang dry by several hours. I noticed after my last wash, that the shirt had 3 small holes appear on the right torso side of my shirt. I would say I averaged about 4 days of wearing these between washes.2) I found that I could wear these products multiple times before washing them because the odor resistance is excellent. I usually wore these 4 times before washing them, and I wore underwear under them to extend their use between washes. I would wear them for about 12-16 hours during the day, then I would change my clothes at night for bed, allowing these to hang dry. Wool certainly has an advantage over synthetics on odor resistance.3) While I normally wore these in temperatures from 10s to 30s, sometimes I would be indoors at 60-70 degrees. While I definitely felt warm and started sweating a little at room temperatures, I did feel that these products breathed and dried well. I never felt these products get soaked like cotton nor unpleasantly damp like polyester while wearing them.4) When soaked (like just after washing), these products need 5+ hours to hang dry. I would say these are not the best for highly humid, wet environments.I had high hopes for my Smartwool 250 Merino base layers, especially since these are highly rated. I must say that if I spend $100 on a baselayer top and $100 on a baselayer bottom, I expect to get more than 25 uses and 12 weeks worth of wear out of them, so I am highly disappointed about the cost to durability/longevity ratio.I guess the search for the best baselayers continues..Cons: -3 stars- This baselayer is not durable at all. I had 3 small holes form after only 5 machine washes and 1 hand wash. (-2 stars for the lack of durability)- This product is expensive, and not worth the price given the fragility of the product. (-1 star for the cost)Pros: +2 stars- This baselayer resists odors extremely well.- This baselayer is extremely soft.- This baselayer does provide adequate warmth and is more breathable than synthetic counterparts.
This is my second pair of these. First pair I purchased about 10 years ago and still going strong and became my go-to base layer for aerobic activities in chilly and cold weather (below 45 F). Second pair is to wear as base layer to office and to give first pair a break between uses. For cold, windy days I recommend using an outer wind-resistant pant. These function extremely well across a wide range of temperatures. For sedentary office conditions these feel fine under a pair of pants and I have never experienced sweating or discomfort. When I step outside on a cold day to clean snow off the car or just take a walk, they are great to have on underneath.
I already own three pairs of these long Johns and purchased a fourth pair because you can never have enough Long Johns in Canada. The merino wool blend is high quality - able to wick away moisture from sweat and doesn't hold onto odours for long. I have a thinner body type, so Smartwool fits tight against my skin which makes it feel warmer in winter. Nice colour selection and nice fit. That is why I own so many.
