How to Choose Base Layers
REI Co-op Midweight Base Layer Half-Zip Top - Women's
$29.83Compared to $59.95*Save 50%
The perfect layering companion for skiing and cold-weather hiking, the women's REI Co-op Midweight base layer half-zip top offers warmth in the cold and easy venting thanks to a front zipper.
- Recycled polyester/spandex has a smooth face so layers slide on easily and is peached for a supersoft next-to-skin layer
- Fabric wicks moisture and dries quickly to keep you comfortable
- Partial zip neck to dump heat and provide ventilation if you need a little cooling down
- Spandex adds the right amount of stretch combined with underarm gussets to maximize your range of motion
- Flatseam construction reduces bulk and chafing, and rolled-forward shoulder seams prevent abrasion from pack straps
- Thumbholes hold sleeves in place and help seal warmth in
- UPF 50+ rating protects against sun rays
- Contains materials that meet the bluesign® criteria
- 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 Certified™ factory
Imported.
View all REI Co-op Women's Base Layer Tops| Best Use | Multisport |
|---|---|
| Shirt Type | Partial-zip |
| Fabric | 92% recycled polyester/8% spandex (bluesign® approved) |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Midweight |
| Sleeve Length | Long Sleeve |
| Thumbholes | Yes |
| Gender | Women's |
| Sustainability | Contains materials that meet the bluesign® criteria Contains recycled materials Fair Trade Certified™ factory From a Climate Label Certified brand |
REI Co-op Clothing - Women's
| XXS | XS | S | M | L | XL | 1X | 2X | 3X | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18W | 20W | 22W | 24W | 26W | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Numerical Size | 00 | 0-2 | 4-6 | 8-10 | 12-14 | 16 | 18 | 20-22 | 24-26 | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | 26 |
| Bust | 31 | 32-33 | 34-35 | 36-37 | 38.5-40 | 41-42.5 | 43-45 | 47-49 | 51-53 | 32 | 33 | 34 | 35 | 36 | 37 | 38.5 | 40 | 42.5 | 45 | 47 | 49 | 51 | 53 |
| Sleeve Length | 29.5 | 30 | 30.5 | 31 | 31.5 | 32 | 32.5 | 33.5 | 34.5 | 30 | 30 | 30.5 | 30.5 | 31 | 31 | 31.5 | 31.5 | 32 | 32.5 | 33.5 | 33.5 | 34.5 | 34.5 |
| Waist | 24.5 | 25.5-26.5 | 27.5-28.5 | 29.5-30.5 | 32-33.5 | 34.5-36.5 | 37.5-39.5 | 40.5-42.5 | 44.5-46.5 | 25.5 | 26.5 | 27.5 | 28.5 | 29.5 | 30.5 | 32 | 33.5 | 36 | 38.5 | 40.5 | 42.5 | 44.5 | 46.5 |
| Hip | 34 | 35-36 | 37-38 | 39-40 | 41.5-43 | 44-46 | 47-49 | 50-52 | 54-56 | 35 | 36 | 37 | 38 | 39 | 40 | 41.5 | 43 | 45.5 | 48 | 50 | 52 | 54 | 56 |
| Inseam | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements. Some women's pants are available in petite and tall sizes. Typically petite sizes fit women 4'11" to 5'3". Regular sizes fit women 5'4" to 5'8". Tall sizes fit women 5'9" to 5'11".
PETITE: Generally, as compared to regular sizes, petite sizes are 2.5 inches shorter in inseam, 1 inch shorter in body length, 1.25 inches shorter in sleeve length and ¾ inch shorter in total rise.
TALL: tall sizes are 3 inches longer in inseam, 2 inches longer in body length, 2.5 inches longer in sleeve length and 1.25 inches longer in total rise.
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
More expert advice
Better gear is built together
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.
Review this Product
Adding a review will require a valid email for verification
Most Helpful Favorable Review
Excellent performance, wears well, comfortable
KermitB2 years ago
Received free productI'm very picky when it comes to base layers because not only do I require them to aide in keeping me warm, I demand that they are comfortable and can also be used as a pull-over in a pinch. Whether backpacking or running kids to practice, I don't want to carry a lot and need each item I do carry to have multiple uses. I also want clothing items to be easy to wash and dry.
So, why do I love the REI Co-op Women's Midweight Base Layer half-zip so much? It checked all my boxes and here's how...
Over two weeks, I was able to use this base layer to sleep in while camping; as a pull-over (sweatshirt) during the day while taking kids to school, practice, and while running errands; and I also wore it on a boat trip as an extra layer under my jacket. Not only did it work to keep me warm when needed, it was super comfortable in every situation.
This half-zip wore well multiple days in a row without bunching or pilling, washed well, dried well both in a dryer and hung up to air dry, and never had seams that rubbed my skin weird. As a larger woman, sometimes a seam will leave a red mark or a raw spot - not this base layer. The seams are sewn flat and the armpit area has a diamond like pattern so the seams do not meet together in one spot. I love this feature because it eliminates irritation. I wore this base layer against my skin, over a tee-shirt, and over a tank-top. It also did not ride up on me while wearing it throughout the day or while using my arms overhead. The fit of this base layer was as expected. I did not feel it ran small or large and would order my normal size again.
Another comfort feature that I can stand behind is the material in which this base layer is made. Unlike other base layers that I've worn over the years, it was not clingy or itchy when I was really warm and ready to take off a layer. The material is very soft, yet durable. It doesn't look or feel like it will fall apart.
Features that this base layer also has that were nice but not a make-it-or-break-it for me were the thumb holes (I'm sure I'll love these this winter), and the 1/4 zip. I love 1/4 zips and tend to purchase them over other types of base layers, but had this been a full-zip, or no-zip, I believe I would have loved this midweight base layer just as much.
I would recommend the REI Co-op Women's Midweight Base Layer Half-Zip to anyone looking for a very comfortable, easy-to-care-for mid-weight layer for their wardrobe or to add to their outdoor gear list.
KermitBReceived free product
San Diego, CA
78 people found this review helpful
Most Helpful Critical Review
Fit is very small in chest
Pnwhiker2 years ago
Received free product**The person in the photos is my friend who wears an XS and is about 5’6” and 115 lb. She is wearing a size L, which is what I normally wear. The chest is way too small on me, so I’ve opted not to post a photo of myself.**
First off, I have been an REI member for nearly 20 years and love their products. This was the first REI brand item that I felt was not up to par.
I was excited to receive this half-zip top and wanted to love it, but ended up disappointed. Most of my disappointment stems from the sizing. This top is unfortunately not meant for anyone with a real chest, despite showing curvy models wearing it. Even as a base layer, the tightness is uncomfortable for me in the chest. It’s actually pretty loose in the belly, defeating the base layer warmth. It seems to be a weird cut. I don’t know that going up a size would be helpful, but I didn’t have that option.
I received a L, which is usually what I wear, but my friend who is a XS tried it on and it is only slightly big. The top is also long in the back and hits at a weird spot. I have several of these type of base layers from other brands and they all fit fine, all large or even some medium. I’d just go with a long underwear top instead of this product…they’re basically the same.
Pros: I do like the thumb loops on the sleeves and it seems to be fairly warm. The fabric is soft. The yellow color is bright and cheerful.
Cons: sizing is very small and cut is awkward. Not for anyone with a bigger chest (or any chest).
PnwhikerReceived free product
Eugene, OR
52 people found this review helpful
Customer Images
KermitB
Received free product
San Diego, CA
Excellent performance, wears well, comfortable
2 years ago
I'm very picky when it comes to base layers because not only do I require them to aide in keeping me warm, I demand that they are comfortable and can also be used as a pull-over in a pinch. Whether backpacking or running kids to practice, I don't want to carry a lot and need each item I do carry to have multiple uses. I also want clothing items to be easy to wash and dry. So, why do I love the REI Co-op Women's Midweight Base Layer half-zip so much? It checked all my boxes and here's how... Over two weeks, I was able to use this base layer to sleep in while camping; as a pull-over (sweatshirt) during the day while taking kids to school, practice, and while running errands; and I also wore it on a boat trip as an extra layer under my jacket. Not only did it work to keep me warm when needed, it was super comfortable in every situation. This half-zip wore well multiple days in a row without bunching or pilling, washed well, dried well both in a dryer and hung up to air dry, and never had seams that rubbed my skin weird. As a larger woman, sometimes a seam will leave a red mark or a raw spot - not this base layer. The seams are sewn flat and the armpit area has a diamond like pattern so the seams do not meet together in one spot. I love this feature because it eliminates irritation. I wore this base layer against my skin, over a tee-shirt, and over a tank-top. It also did not ride up on me while wearing it throughout the day or while using my arms overhead. The fit of this base layer was as expected. I did not feel it ran small or large and would order my normal size again. Another comfort feature that I can stand behind is the material in which this base layer is made. Unlike other base layers that I've worn over the years, it was not clingy or itchy when I was really warm and ready to take off a layer. The material is very soft, yet durable. It doesn't look or feel like it will fall apart. Features that this base layer also has that were nice but not a make-it-or-break-it for me were the thumb holes (I'm sure I'll love these this winter), and the 1/4 zip. I love 1/4 zips and tend to purchase them over other types of base layers, but had this been a full-zip, or no-zip, I believe I would have loved this midweight base layer just as much. I would recommend the REI Co-op Women's Midweight Base Layer Half-Zip to anyone looking for a very comfortable, easy-to-care-for mid-weight layer for their wardrobe or to add to their outdoor gear list.
Age:45–54
Weight:200–225 lbs.
Height:5'6"
Yes , I recommend this product
Sarah
Received free product
Amarillo, TX
Great quality, flexible fit
2 years ago
This is a high quality base layer suitable for a variety of activities. It kept me warm on brisk morning walks, and on cold morning drives to the trailhead. It dries quickly and doesn't hold smell like a lot of other synthetic materials. As an active, larger chested person, I often alternate between medium and large tops. This large fit me perfectly, and the half-zip allows for more flexibility. Though the material is somewhat stretchy (which usually means an unflattering fit for me), the half-zip allows for a more flattering fit. The thicker material makes for a cozy top that's really appreciated on early, cold mornings. The thumb holes are also a nice touch, especially when I choose to go gloveless, knowing the temps will rise soon after I leave the trailhead. Nice, versatile top - would recommend!
Age:25–34
Weight:150–175 lbs.
Height:5'7"
Yes , I recommend this product
rojerotmg
Richmond, VA
Versatility Perfected
2 years ago
I have 3 quarter zip base layers from the REI brand. They are still in wonderful condition but I was looking for a neutral cream/brown. They released one in the Active Pursuits line but it felt too plasticky, not like the cottony ones I love. THIS IS IT! I’m 5’6” 153lbs, 34DD, 28” waist. I like my tops to fit snugly without restriction, I got a small and it fits perfectly. The offset shoulder seams accommodate my broad shoulders, the sleeves are long enough for my gorilla arms while being snug for layering. The zipper chokes me a bit since I should have gotten a medium, but it would have been too much fabric around the waist. I’m so unbelievably pleased, I shall be purchasing more colors immediately.
Age:25–34
Weight:150–175 lbs.
Height:5'6"
Yes , I recommend this product
Pnwhiker
Received free product
Eugene, OR
Fit is very small in chest
2 years ago
**The person in the photos is my friend who wears an XS and is about 5’6” and 115 lb. She is wearing a size L, which is what I normally wear. The chest is way too small on me, so I’ve opted not to post a photo of myself.** First off, I have been an REI member for nearly 20 years and love their products. This was the first REI brand item that I felt was not up to par. I was excited to receive this half-zip top and wanted to love it, but ended up disappointed. Most of my disappointment stems from the sizing. This top is unfortunately not meant for anyone with a real chest, despite showing curvy models wearing it. Even as a base layer, the tightness is uncomfortable for me in the chest. It’s actually pretty loose in the belly, defeating the base layer warmth. It seems to be a weird cut. I don’t know that going up a size would be helpful, but I didn’t have that option. I received a L, which is usually what I wear, but my friend who is a XS tried it on and it is only slightly big. The top is also long in the back and hits at a weird spot. I have several of these type of base layers from other brands and they all fit fine, all large or even some medium. I’d just go with a long underwear top instead of this product…they’re basically the same. Pros: I do like the thumb loops on the sleeves and it seems to be fairly warm. The fabric is soft. The yellow color is bright and cheerful. Cons: sizing is very small and cut is awkward. Not for anyone with a bigger chest (or any chest).
Weight:150–175 lbs.
Height:5'10"
No, I do not recommend this product
Kathy
North Andover, MA
Not like they used to be!
1 year ago
I have several of these midweight half zip base layers I've bought over the years, as they've been my favorite for all my fall/winter/spring outdoor activities. However, the one I bought most recently is not satisfactory - the fabric is not as soft and stretchy, and the fit is smaller all over, but especially in the shoulders, chest, and armpits. After realizing that I'm always uncomfortable when I wear this one, I compared it to an older one, and the size difference was obvious. I'll put this one in my recycling pile, and I'm sorry the ones I loved are no longer available, as I have a couple that are finally wearing out that I'd like to replace.
Age:65–74
Weight:125–150 lbs.
Height:5'5"
No, I do not recommend this product
WA campfishhike
Eastern Washington State
REI women's midweight base layer half-zip top
2 years ago
The fabric feels very nice against the skin, and the color matched the website picture. The fit was as described.. close-fitting enough to layer under another shirt, sweater or jacket, yet not stretched-out/skin-tight, and allows very comfortable range of motion. The thumb slots are great for keeping sleeves in place while donning another shirt or layering under a sweater or fleece. The sleeve length and thumb slots help to keep wrists well-covered. Zipper works easily/smoothly, and the neck is very comfortable whether fully zipped up or open. I'm loving this shirt for the unsettled spring weather, whether indoors or out walking, bird watching, and other favorite outdoor activities.
Age:55–64
Weight:200–225 lbs.
Height:5'7"
Yes , I recommend this product
Melleanp
Received free product
Chandler, AZ
Perfect top for all the things
2 years ago
I absolutely love this top! Perfect on a recent trip to Flagstaff, around the house, and even for a day in the clinic. The midweight is just right to keep me warm and the color is fabulous. Now I just have to keep it away from my 16-year-old daughter’s closet!
Age:45–54
Weight:125–150 lbs.
Height:5'9"
Yes , I recommend this product
Dream Catcher
Received free product
Everett, WA
Not just for the trail...
2 years ago
I've had this shirt for about 3 months now and have been able to put it to the test. It's a winner. It's very comfortable and easy to launder. The zipper is nice and long so it's easy to vent "as needed." I appreciate the thumb hole option which keeps any drafts out between the end of my sleeve and the top of my glove. The only drawback is the extra effort it takes to read my watch - worth it to me, though. Ok, time for my true confession: I've even worn it as a pajama top! Hey, what can I say? I sleep with my window wide open!
Height:5'6"
No, I do not recommend this product
SavSandra
San Diego
True to size
1 year ago
Im normal between small and medium. I originally purchased a large in this after reading reviews that mentioned it ran small. I was swimming in a large and had to exchange for a medium. The fabric is soft and has some stretch, seams are not scratchy and love the green color. It’s a bit long for my height as it comes down to bottom of hips but not a deal breaker. My bust is 34B, waist currently 30 due to health issues and hips are 40’. I hope my review helps as measurements are hardly ever included in reviews.
Age:45–54
Weight:125–150 lbs.
Height:5'3"
Yes , I recommend this product
Avid Adventurer
Changed for the worse!
1 year ago
I agree with a large number of other reviews. This midweight base layer has changed. It is cut smaller than previous versions and uses a different fabric. I have lots of the 1/2 zip and cre ex versions of the Co-op midweight base layer and love them. When a new color is released I usually buy it. Not anymore! These are now smaller and instead of being soft and comfortable the new fabric is scratchy when stretched against the skin. As a base layer I can do without scratchy!
Height:5'7"
Age:65–74
Weight:125–150 lbs.
No, I do not recommend this product
1 - 10 of 137 Reviews