How to Choose Base Layers
REI Co-op Lightweight Base Layer Long-Sleeve Crew Top - Men's
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The men's REI Co-op lightweight long-sleeve base layer crew keeps you warm until you warm up, then wicks sweat to keep you comfortable when you're going hard.
Shop similar products- Made of a soft, snag-resistant polyester blend that wicks sweat and dries fast to keep you warm in winter and cool in summer
- Spandex in the blend gives the fabric 4-way stretch, while underarm gussets ensure you can reach and move with ease
- Flatseam construction is comfortable against your skin
- Lower back hem stays tucked when you stretch
- UPF 50+ sun protection
- Semifitted
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
- Made in a Fair Trade Certifiedâ„¢ factory
- Contains materials that meet the bluesign® criteria
Imported.
View all REI Co-op Men's Base Layer Tops| Best Use | Multisport |
|---|---|
| Shirt Type | T-shirt |
| Fabric | 92% polyester/8% spandex (bluesign® approved) |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Lightweight |
| Sleeve Length | Long Sleeve |
| Gender | Men's |
| Sustainability | Contains materials that meet the bluesign® criteria Fair Trade Certified™ factory From a Climate Label Certified brand |
REI Co-op Clothing - Men's
| XS | S | M | L | XL | XXL | XXXL | 24 IN Waist | 26 IN Waist | 28 IN Waist | 30 IN Waist | 31 IN Waist | 32 IN Waist | 33 IN Waist | 34 IN Waist | 35 IN Waist | 36 IN Waist | 38 IN Waist | 40 IN Waist | 42 IN Waist | 44 IN Waist | 46 IN Waist | 48 IN Waist | 50 IN Waist | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chest | 35 | 36 - 38 | 39 - 41 | 42 - 45 | 46 - 49 | 50 - 53 | 54 - 57 | |||||||||||||||||
| Sleeve Length | 32 | 32.5 | 33 | 33.5 | 34 | 34.75 | 35.5 | |||||||||||||||||
| Waist | 27.5 | 28 - 30 | 32 - 34 | 36 - 38 | 40 - 42 | 44 - 46 | 48 - 50 | 24 | 26 | 28 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 |
| Hip | 33.5 | 34.5 - 36.5 | 37.5 - 39.5 | 41 - 43 | 44 - 46.5 | 47.5 - 50.5 | 51.5 - 54.5 | 32 | 33.5 | 34.5 | 36.5 | 37 | 37.5 | 38.5 | 39.5 | 40.25 | 41 | 43 | 44 | 46.5 | 47.5 | 50.5 | 52.5 | 54.5 |
| Inseam | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements.
SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes.
TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.
Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.
Inseam is measured to the floor.
Buying Advice
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From feedback to field testing, all of our gear is dialed-in by REI Co-op members. Their adventures informed every stitch and detail—making for better, longer-lasting gear.
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Most Helpful Favorable Review
A little short
kobethebuff4 years ago
The material feels a little scratchy to me. I’m 6’1 215 lbs and the XL was a bit short in length. I wish the shirt was another inch or two longer. Then bought an XXL and it was too big overall, though the length was good.
kobethebuff
CO
16 people found this review helpful
Most Helpful Critical Review
Notable downgrade from prior product years
Daniel5 years ago
The change in fabric type/construction from years past has resulted in an inferior feel, fit, and function (look at the zoomed-version to see the obviously more 'slick' fabric with little 'holes'). This is a tragedy, as the previous REI baselayers were the most well-constructed, best fitting, and functional baselayers I'd found in *years* of searching. Why change something that was working so well? Really a bummer.
Daniel
Portland, OR
43 people found this review helpful
Customer Images
Augustine
Hudson Valley, NY
Wash it then wear
1 year ago
It was supper itchy at first wear, washed it and gave it another shot. Kept me dry and not holding odor which isn’t something I’m fond of.
Age:25–34
Weight:150–175 lbs.
Height:5'6"
Yes , I recommend this product
IanOnTrail
Kansas
Comfortable on trail
4 years ago
Purchased this shirt a few weeks ago to do some hiking in. This past weekend I wore it for a 2 day one night backpack for 10 miles. The shirt was comfortable, provided nice protection and dried quickly! However, the seams already coming apart after 1 use!
Age:25–34
Weight:150–175 lbs.
Height:5'11"
No, I do not recommend this product
Zero
Las Vegas, NV
Super comfortable synthetic base
3 years ago
Very comfortable synthetic base layer. I normally wear a size Large t shirts and the medium fit me perfect for a fitted but not tight fit. The material is very soft and didn’t irritate my skin at all. Super breathable and light weight. Unfortunately if you’re a sweater like me, it will get smelly pretty quickly if you’re in any kind of warmth. If you’ve got issues with BO or just sweat a lot, I’d probably recommend a different material like wool or cotton for multi day use. However, If you’re in a humid climate and need something to keep you out of direct sunlight for a day or less, I would definitely recommend.
Age:25–34
Weight:150–175 lbs.
Height:5'6"
Yes , I recommend this product
Alex
Tempe, AZ
stretched and became baggy
2 years ago
This shirt became very baggy after about a year of moderate use. It was a great shirt for many uses – hiking, backpacking, sleeping, grocery shopping… But at some point, it just grew a size or two. Now I have to roll up the sleeves to find my hands, and it’s too baggy to use as a base layer. All the seams are intact, and the shirt has held up great other than that. I wash it in a front-load machine and hang it to dry. A customer service person at my local REI suggested the spandex (8%) may have given out. My photo shows this shirt (blue) with a REI Active Pursuits shirt (100% polyester, green) on top. Both are size small, similar vintage, and both fit similarly at first. You can see how the base layer shirt has grown. I’m retiring this shirt and getting another Patagonia Capilene base layer shirt. The Capilene turns out to be a better value for me.
Age:55–64
Weight:125–150 lbs.
Height:5'6"
No, I do not recommend this product
xtraspicy
fantastic baselayer ruined by poor seams
5 years ago
I really wanted to like this baselayer. I have two of these and two of the REI co-op sahara base layers which are similar but are 30 UPF instead of 50. This base layer top had everything I wanted, the fit is good, comfort is good, and the sweat wicking and temperature regulation is good. I typically wear it for outdoors activity and underneath a motorcycle jacket where it massively improves airflow and comfort. Unfortunately, on both shirts I have, the bottom seam at the hem came apart completely. I'm hoping the rest of the shirt doesn't come apart like this, but only time will tell. I would have marked this one star, but had to give it at least two because aside from the seam at the meh, it really is a great base layer.
Height:5'10"
Weight:150–175 lbs.
No, I do not recommend this product
Doubletap57
Statesboro, Ga
Getyou one
1 year ago
Another quality R.E.I. product. Bought as a baselayer for a grand canyon hike in February, worked flawlessly.
Age:55–64
Weight:250–275 lbs.
Height:6'3"
Yes , I recommend this product
Nips
CT
Love it - close to Merino
7 months ago
This base layer has been perfect for my running and hiking adventures. It’s lightweight and breathable, which means I stay comfortable and dry whether I’m tackling steep trails or pounding the pavement on a chilly morning. The fabric wicks away sweat efficiently, so I don’t feel clammy even during high-intensity workouts. What I love most is how versatile it is. It works great as a standalone layer in cooler weather and fits seamlessly under a jacket when temperatures drop further. It’s soft, moves with me, and doesn’t chafe, even during longer outings. For the price, it’s hard to find something that performs this well for both running and hiking.
Age:25–34
Weight:150–175 lbs.
Height:6'0"
Yes , I recommend this product
Daniel
Portland, OR
Notable downgrade from prior product years
5 years ago
The change in fabric type/construction from years past has resulted in an inferior feel, fit, and function (look at the zoomed-version to see the obviously more 'slick' fabric with little 'holes'). This is a tragedy, as the previous REI baselayers were the most well-constructed, best fitting, and functional baselayers I'd found in *years* of searching. Why change something that was working so well? Really a bummer.
No, I do not recommend this product
Bozo
Bay Area, CA
Unfortunately uncomfortable.
2 years ago
I tried one on in the store and found it itchy. I wrongfully assumed that was the starch some retailers apply to new clothing in order to keep it free from wrinkles, and figured it would wash out. After washing it a half-dozen times, it's still itchy. It wicks moisture well enough, but it feels like I'm wearing a burlap sack. Save yourself the trouble and spend a little more to get a Capilene Cool Daily from Patagonia. If you still decide to buy it, definitely size up, as my usual size was skin tight.
Age:25–34
Weight:150–175 lbs.
Height:5'10"
No, I do not recommend this product
theJBRU
Minneapollis, MN
Love this layer
5 years ago
This is one of the best updates to a product I've seen. Previous version of the REI Lightweight Base Layer were perfectly adequate, but this is a serious upgrade. I wear these as casual shirts as well as layered beneath a sweatshirt if I need extra warmth. The fabric and construction is now similar to the REI Mid-weight Base Layer, it has a slightly fuzzy interior that helps wick sweat away and a slick-weave exterior that makes sliding it into an outer layer or jacket easy with out getting caught. I've also found that this exterior weave is great at keeping off pet hair.
Yes , I recommend this product
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