How to Choose Base Layers
REI Co-op Merino 185 Long-Sleeve Half-Zip Base Layer Top - Women's
$89.95
Naturally odor resistant, the ultrafine merino wool of the soft, breathable women's REI Co-op Merino 185 long-sleeve half-zip base layer top is ideal for sweating on the trail—and sleeping in a tent.
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- Ultrafine 185 g merino wool offers a soft feel without any itchiness
- Made with 100% merino wool that naturally breathes, wicks away sweat, dries quickly and resists odors, making it an ideal multiday trip companion
- UPF 30 sun protection
- Half-zip front helps with venting; standing collar and chin guard for protection
- Flat seams and merrow stitch construction eliminate chafing
- Underarm gussets allow full range of movement
- Designed to hug the body for optimum performance
- Weight: 6.8 oz. (size Medium)
- Machine wash warm, gentle cycle, with wool wash product; do not twist or wring; remove promptly; do not bleach; tumble dry low; dry cleaning not recommended
- Field-tested on its own and as a base layer while hiking, running, rock climbing, cycling, skiing and camping in diverse climates across the U.S.
- 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 the REI Co-op Merino 185 Product LineView all REI Co-op Women's Base Layer Tops| Best Use | Multisport |
|---|---|
| Shirt Type | Partial-zip |
| Fabric | Merino wool |
| Sun-Protective Fabric | Yes |
| UPF Rating | 30 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Lightweight |
| Sleeve Length | Long Sleeve |
| Gender | Women's |
| Sustainability | 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.
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Most Helpful Favorable Review
Slight Style change
Norwaygrrl3 years ago
I’ve purchased a couple of these merino base layer tops over the last two years and I absolutely love them. I wear them mostly as a single layer as I run warm. I’m always so delighted that merino doesn’t smell plus regulates my temp well and it’s a great weight - not bulky.
I’m disappointed however that this year’s version has a shorter and much looser neck. It’s not easy to find a taller, mock-style turtleneck with a zipper that has a garage…this top “used to” have it all. Now the neck is way too loose on the woman’s, but the men’s is still tall and close-fitting. Why change the women’s?
Norwaygrrl
Kent
41 people found this review helpful
Most Helpful Critical Review
Slight Style change
Norwaygrrl3 years ago
I’ve purchased a couple of these merino base layer tops over the last two years and I absolutely love them. I wear them mostly as a single layer as I run warm. I’m always so delighted that merino doesn’t smell plus regulates my temp well and it’s a great weight - not bulky.
I’m disappointed however that this year’s version has a shorter and much looser neck. It’s not easy to find a taller, mock-style turtleneck with a zipper that has a garage…this top “used to” have it all. Now the neck is way too loose on the woman’s, but the men’s is still tall and close-fitting. Why change the women’s?
Norwaygrrl
Kent
41 people found this review helpful
Customer Images
Lisa
Seattle, WA
Itchy and large
2 years ago
I ordered the REI Merino Long-Sleeve Half Zip in SHADED SUMAC in a large. The seams were nicely done and it’s a beautiful color. I am returning it because it was really itchy, the zipper was an awkward length on me, and it was baggier than I like. I’m 5’6”, 37” bust, 30” waist, 45” hip and I think a medium would have fit better.
Age:25–34
Weight:150–175 lbs.
Height:5'6"
No, I do not recommend this product
Norwaygrrl
Kent
Slight Style change
3 years ago
I’ve purchased a couple of these merino base layer tops over the last two years and I absolutely love them. I wear them mostly as a single layer as I run warm. I’m always so delighted that merino doesn’t smell plus regulates my temp well and it’s a great weight - not bulky. I’m disappointed however that this year’s version has a shorter and much looser neck. It’s not easy to find a taller, mock-style turtleneck with a zipper that has a garage…this top “used to” have it all. Now the neck is way too loose on the woman’s, but the men’s is still tall and close-fitting. Why change the women’s?
Age:55–64
Weight:150–175 lbs.
Height:5'6"
Yes , I recommend this product
Teacosy
Pacific Northwest
Reliable layer
3 years ago
This became my go-to layer during a holiday visit with family. It’s easy to wear and perfect for me as someone who gets warm quickly while exercising. On colder days, I layered it over a snug long-sleeved shirt and under a down coat and scarf. On warmer days, it was perfect over a tank, with the option to zip up to my chin or zip down fully to vent excess heat. My only grumble: As some other reviewers said, the neck is a bit loose and droops or distorts in odd ways when it’s zipped all the way up. I mostly wear it half-open with the collar folded out on both sides.
Age:35–44
Weight:125–150 lbs.
Height:5'5"
Yes , I recommend this product
FLhikester
Central FL
Perfect for mid-Nov hiking in New Mexico!
2 years ago
Bought just one of these (in the red) to take as a base layer while road-tripping and hiking around various parts of NM. Temps range from low 60's to low 20's. It was perfect on its own at the higher temps. Wore it with another long-sleeved layer and a puffer jacket at the lower temps and in the wind. Breatheability is perfect, it never got stinky (one of the great benefits of wool!), and it hand-washed up well in wool-care detergent. As others have said, I found it slightly itchy when I first put it on each day, but pretty soon my nervous system forgot about it and I was fine. I'll be buying several more since this will be a great winter top on its own in our mild FL winters.
Age:35–44
Weight:150–175 lbs.
Height:5'5"
Yes , I recommend this product
Amanda
Received free product
Portland, Oregon
Comfortable, soft
4 years ago
- Roomy enough to easily layer over something else (good for the large-busted, might run too large if you're not) - Comfortable, very soft fabric (so I didn't want to layer it!) - Kept me cool when worn as a single layer, and warm when layered; has a long enough zipper on the front to really help when I started to overheat (but not so long that I was exposing myself) - Great color - Unfortunately the fabric pilled quite a lot on the back during first wearing, where it rubbed against my daypack (that said...it survived the washing machine with no further damage, and kept its size - hung to dry). For this reason, I'm giving it a "good" instead of "great" rating. I'll use this top often, nice for cool mornings/evenings during summer camping and for spring/fall hikes.
Age:45–54
Weight:150–175 lbs.
Height:5'3"
Yes , I recommend this product
UTSkr
Salt Lake City, UT
Great base layer for skiing
6 months ago
I purchased this to use as a base layer for skiing and love it. It's the perfect weight for most days keeping me warm without overheating. On really cold days, I will layer an additional similar-weight merino wool top and it's perfect. I wanted a top with a neck, and preferred one without a zipper, but this was the only option. I was worried about the zipper rubbing, but there was no issue! There is a lining behind the zipper on the neck so it is nice a soft. The top is a bit long and I'm shorter (5' 2"), so it falls lower than my hips. I like the longer length, so I can tuck it into my ski pants and avoid cold drafts. Extremely happy with this base layer!
Age:45–54
Weight:100–125 lbs.
Height:5'2"
Yes , I recommend this product
Meg D
CA
Too bad they shortened the zipper
2 years ago
I bought this top because I have an earlier version (from around 2018) that I love and which has a long zipper that makes breast feeding easy. Unfortunately REI has decided to make the zipper shorter like all other thermal tops from competitors. I haven’t been able to find a new thermal top with a true half zip this season anywhere. Luckily I was able to swap this new one for my mom’s old one from 5 years ago. Just another inch or two on the zipper would make this top useful to me.
Age:35–44
Weight:125–150 lbs.
Height:5'1"
Hikebiker
Versatile 100% RWS Wool/Fair Trade Top Baselayer
2 years ago
I look for clothes that are 100% natural fibers and this Merino 185 top fits the bill. I like this top because it wears well, doesn't take up odors, and is a great base layer. I have a few others that I've had for a few years and they are well made with good colors. They are RWS wool, which is a third party certification that insures that the sheep were well taken care of, and they are Fair Trade, so the makers are paid fairly. I have brought these for travel and camping. They don't take up much backpack space. The half zip makes the top versatile from cool mornings to warmer afternoons. Clothes with blended natural and synthetic fibers can't break back down to the environment. Buy all natural fiber clothes when you can.
Age:65–74
Weight:100–125 lbs.
Height:5'3"
Yes , I recommend this product
Meshal
Santa Fe, NM
comfy and cozy
2 years ago
Fabric is very soft and provides plenty of warmth. Seemed to dry quickly after sweating. Best to wear this under another layer; I wore it alone while hiking through heavy brush and noticed a lot of wear/wisps on the fabric and stitching.
Age:25–34
Weight:175–200 lbs.
Height:5'5"
Yes , I recommend this product
akstyle86
Received free product
Anchorage, Alaska
Super comfortable and flattering
4 years ago
This top is super cute and comfortable! It doesn't have the itchy wool feel, and the dark teal is a really nice color. The cut is flattering yet not skin tight or too loose. I wore this for remote fieldwork in Arctic Alaska (~40 degrees F) under a thin synthetic jacket, and it kept me comfortable, dry, and warm. I am 5'2" and 120 lbs and the XS fit perfectly.
Age:35–44
Weight:100–125 lbs.
Height:5'2"
Yes , I recommend this product
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