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.
Designed to keep you warm and wick away moisture, the REI midweight half-zip base layer is ideal for high-performance cold-weather outdoor activities.
Shop newer version- Made of a durable yet soft polyester / spandex blend that wicks sweat and dries fast
- Tall neck extends coverage; zipper with chin guard lets you adjust ventilation
- Flatseam construction, raglan sleeves and side gussets are comfortable as you move
- Extended back hem stays tucked in when you lean forward
- UPF 50 sun protection
- Fitted
- 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
| Best Use | Multisport |
|---|---|
| Shirt Type | Partial-zip |
| Fabric | Polyester |
| 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.
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
7 people found this review helpful
8 years ago
Perfect for layering or a light long sleeve pullov
I purchased specifically for a camping/ hiking trip. It was lightweight/wicked sweat away during the hike and helped provide coverage from the sun without being too hot. As it got colder in the night, since this is form fitting, it was very easy to throw a heavier jacket on over it. Highly recommend!!
Yes , I recommend this product
Sunshine
Henderson, NV, United StatesMost Helpful Critical Review
7 people found this review helpful
7 years ago
Sized too small
I have several other REI shirts in the same size. This particular one was cut weird - way smaller than usual for their usual sizing. I'd recommend going up a size, or just skipping the purchase. Also felt more like light weight instead of mid weight. If it fits you and it's on sale, may be worth looking into. Def not full price.
No, I do not recommend this product
HappyHikerHop
Kitsap County, WA, United StatesLocation:Henderson, NV, United States
8 years ago
Perfect for layering or a light long sleeve pullov
Yes , I recommend this product
I purchased specifically for a camping/ hiking trip. It was lightweight/wicked sweat away during the hike and helped provide coverage from the sun without being too hot. As it got colder in the night, since this is form fitting, it was very easy to throw a heavier jacket on over it. Highly recommend!!
Location:Long Beach, CA, United States
8 years ago
Keeps me warm
Yes , I recommend this product
This is my 3rd REI base layer. It is safe to say I love them. I get cold easily and it keeps me warm. During activity it breaths well. I also wear it as a top layer to another non zip base layer. It also drys fairly quick considering how thick the material is.
Location:Bishop, CA, USA
7 years ago
Great Fitting Comfort and Warmth
Yes , I recommend this product
I bought two and liked them so much that I got two more. The sleeves are nice and long, the shape is feminine without being tight or bunchy, the shirt launders well and it can be rolled for wrinkle-free travel. I love the fit, and believe me, I'm not built like the models! I would only caution that this shirt is somewhat heavy, so maybe not the best for traveling if weight is a big consideration. But I've worn these skiing, hiking, horse-back riding, and also thrown them in a suitcase just for lounging and love them.
Location:Kitsap County, WA, United States
7 years ago
Sized too small
No, I do not recommend this product
I have several other REI shirts in the same size. This particular one was cut weird - way smaller than usual for their usual sizing. I'd recommend going up a size, or just skipping the purchase. Also felt more like light weight instead of mid weight. If it fits you and it's on sale, may be worth looking into. Def not full price.
Location:Knoxville, TN
8 years ago
Great by itself or layering
Yes , I recommend this product
Love it! It is fitted so it doesn't create bulk. The extra length keeps it from creeping up.
Location:Wilton, CA
9 years ago
Perfect Weight
Yes , I recommend this product
This is the perfect weight for outdoor activities in the fall. It looks very neat and still looks and feels brand new after each washing. I liked this so much I bought on in every color! Too bad there were only 3 colors!
Location:Newark, DE, United States
8 years ago
warm, comfortable
Yes , I recommend this product
I love this product but it should be known that I have purchased a variety of colors and weights in these so comfortable tops from a variety of brands.
7 years ago
Warm and Comfortable
Yes , I recommend this product
I love this top. It is warm and soft and looks great. I wish I could find it in other colors because I would buy them too. I found it on a clearance rack and hope they have not discontinued this.
Location:Colorado, United States
8 years ago
Snug and comfy
Yes , I recommend this product
Love the torso length. I always have trouble with things being to short in the torso. Color is great. I'm 5'7", 125lbs... small fits perfectly and I still say that after washing it.
Location:Austin, TX, United States
7 years ago
Love this shirt!!!
Yes , I recommend this product
I wear this everyday as a comfy and warm shirt. I also wore it skiing as my only layer under my Marmont coat in 30 degree weather; it was breathable but super warm!
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