How to Choose Base Layers
REI Co-op Midweight Base Layer Half-Zip Top - Women's
This product is not available. Good news: we have a newer version.
An ideal first layer for playing hard on cold days, the women's REI Co-op Midweight Base Layer half-zip top offers the warmth of long sleeves and easy venting thanks to a front zipper.
Shop newer version- Smooth outer face lets layers slide on easily, while a brushed interior provides warmth
- High neck coverage with a half-zip front lets you open up for venting when you're working hard
- Fabric wicks moisture and dries quickly to keep you comfortable
- 4-way stretch delivers a flexible range of motion
- Flatseam construction reduces bulk and chafing, and rolled-forward shoulder seams prevent abrasion from pack straps
- UPF 50+ rating protects against sun rays
- 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
Imported.
View all REI Co-op Women's Base Layer Tops| Best Use | Multisport |
|---|---|
| Shirt Type | Partial-zip |
| Fabric | 92% polyester/8% spandex |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Midweight |
| Sleeve Length | Long Sleeve |
| Gender | Women's |
| Sustainability | 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.
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Most Helpful Favorable Review
Favorite layer for everything
JWinSF3 years ago
I've bought various base layers over the years and this is definitely the softest and best quality for the price...in fact it's better than more expensive options IMO. It doesn't snag on my rough athlete hands, it keeps me warm, and the fit is flattering. Stands up well to washing so far. The only suggestion I have is to offer solid colors. The heather colors don't go with patterned bottoms. Sizing is as expected. I'm 5'4", 130 lbs, 36B and I ordered a small.
JWinSF
San Francisco
14 people found this review helpful
Most Helpful Critical Review
Not as good as last year's model.
Gidget7 years ago
I've gotten these shirts for the last couple of years. They were called "space dye," I believe. This year, although the fabric still says it is polyester and spandex, it is more like nylon and less like the amazingly soft t-shirt feeling it had before. Doesn't breathe as well. Also, they made the neck WAY tighter when it's zipped up all the way. On the previous model, I used to zip the neck up all the way when it got cold and it was very comfortable - soft and not confining. The new model has a hard edging, doesn't come up as far and is VERY tight. I've been teased about having a skinny (pencil) neck and it's so tight on me that I am not comfortable zipping it up all the way... so I just have to have a cold neck. I really hope REI goes back to the old material and design. I have several and they are my "go to" when I'm in a colder climate.
Gidget
CA
44 people found this review helpful
Customer Images
Elena
Atlanta, Georgia
Great!
4 years ago
Love this top! It is so comfortable! Even days in the 59s i still get hot in this top if i hike and run! (Yes i am from Georgia and think 50s is cold) i haven't been in colder weather than that so i can't speak on that. highly recommend!
Age:25–34
Weight:175–200 lbs.
Height:6'0"
Yes , I recommend this product
Hanalulu
NC
Perfection if you are active!color is awesome
4 years ago
I wear nothing but zip-ip tops since I bought my first REI zip-ip top 7 yrs ago. Its like turtlenecks except way easier to take on/off and the zipper allows you to wear it zipped up or not. Love the lightweight, warmth and pack-able. Its flattering without being overly tight. I wanted to try a color other than Black. This one is styled longer than my older black ones I already have. Its a beautiful color lavender but closeup is a faint multi layer of lavender colors but not obviously annoying. I stick to solid colors normally. Its a very pretty color without being too pink or too purple. A light lavender. I love it!!!
Age:35–44
Weight:100–125 lbs.
Height:5'3"
Yes , I recommend this product
odessa
Perfect for winter hiking
4 years ago
I tested this top out today on a hike that started in the 20s and finished in the 40s. It was breezy and cloudy, but I was toasty warm with this base layer under a fleece and a shell. Most importantly, the moisture wicking was awesome and I never felt myself getting sweaty on the uphills or chilled during breaks. The color I got was "twilight purple heather." It's a stronger purple color in reality than in the picture, which looked rather like a burgundy red. This isn't a problem--I love this color so much! My measurements are 43-40-45, and the XL fits great, just snug enough to make a good base layer, but not too snug.
Height:5'3"
Age:45–54
Weight:175–200 lbs.
Yes , I recommend this product
Laur
Tampa, FL, USA
Great option for base layer!
7 years ago
I was very satisfied with the level of warmth this base layer brought--I was actually too warm with this and my insulated 3-in-1 ski jacket on a slightly warmer day (30s) on the mountain. Overall the feel, stretch, and warmth are perfect. The fit, however, is where my 4 stars come in. I felt that the sleeves were just slightly too short, and the armpits/shoulders are just slightly too snug. I am 5'9'' and 130lbs, slender build, and definitely wish there was a little more give and room and length to this. Would also love to see thumb holes with that extra sleeve length. Otherwise great base layer and very warm!
Yes , I recommend this product
Michelle H
Chapel Hill, NC and Durango, CO
absolute best shirt and mid layer
3 years ago
This shirt is the perfect layer to keep you perfectly warm & not too hot. It’s buttery soft, washes well and provides ample coverage down to my hips, no front or backside hanging out. I like this layer so much and am disappointed it appears to be changed or discontinued. Why is there no medium size available? This shirt is better than all other equivalent options and somehow the lowest price as well. Charge me more and make it again in medium and I will stock up for me and all my kinfolk! I’m wearing the same one over and over again, so save me and my poor family from seeing and smelling this everyday. Thank you for making such a good quality layer.
Height:5'5"
Weight:125–150 lbs.
Yes , I recommend this product
Lisa M
I love this layer!!!!
4 years ago
I loved this layer!! I really wanted to get a merino wool layer, and I just didn’t feel comfortable in it. (i know wool can be awesome, but it just didn’t agree with me). The moment I tried this one on it was soft on my skin and the fit was just perfect. It turned out to be an excellent and light weight layer that still kept me warm when I needed it to during my trip to CO and UT.
Gidget
California
Not as good as last year's model.
7 years ago
I've gotten these shirts for the last couple of years. They were called "space dye," I believe. This year, although the fabric still says it is polyester and spandex, it is more like nylon and less like the amazingly soft t-shirt feeling it had before. Doesn't breathe as well. Also, they made the neck WAY tighter when it's zipped up all the way. On the previous model, I used to zip the neck up all the way when it got cold and it was very comfortable - soft and not confining. The new model has a hard edging, doesn't come up as far and is VERY tight. I've been teased about having a skinny (pencil) neck and it's so tight on me that I am not comfortable zipping it up all the way... so I just have to have a cold neck. I really hope REI goes back to the old material and design. I have several and they are my "go to" when I'm in a colder climate.
JWinSF
San Francisco
Favorite layer for everything
3 years ago
I've bought various base layers over the years and this is definitely the softest and best quality for the price...in fact it's better than more expensive options IMO. It doesn't snag on my rough athlete hands, it keeps me warm, and the fit is flattering. Stands up well to washing so far. The only suggestion I have is to offer solid colors. The heather colors don't go with patterned bottoms. Sizing is as expected. I'm 5'4", 130 lbs, 36B and I ordered a small.
Age:45–54
Weight:125–150 lbs.
Height:5'4"
Yes , I recommend this product
rachel860
Tampa, FL
LOVE!
5 years ago
The is my absolute favorite base layer. I brought one on my Appalachian Trail thru-hike last year, and it made it the whole way with constant use. I still wear it regularly now and doesn’t look worn, so I would give the quality an A+. This shirt is perfect for sleeping in at night, in camp to keep the bugs off, and for hiking when it’s cold out. The fit of this shirt is very flattering, plus so comfy and light. I’m 5’ 8” and ~150 lbs and the medium fits perfectly. I’m back to buy a few more colors.
Yes , I recommend this product
Shannalh
Santa Cruz, CA
All around amazing purchase!
5 years ago
I love this top so much that I ended up ordering a second color. It's the perfect weight for layering or wearing alone on a cool day, and is so comfortable! It's hardy and has withstood many a camping, climbing, and snowboarding trip. It can pack down pretty small so it's easy to stuff into a backpack or suitcase. I'm 5'5"/130 lbs, and purchased size medium. I typically wear tops in a size small, but this small was pretty form-fitting and I wanted a slightly looser fit.
Age:25–34
Weight:125–150 lbs.
Height:5'5"
Yes , I recommend this product
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