How to Choose Base Layers

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Start with a high performing first layer and enjoy your time in the snow more. The women's REI Co-op Midweight base layer tights have a smooth face for easy layering and are brushed inside for warmth.
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View all REI Co-op Women's Base Layer Bottoms| Best Use | Multisport |
|---|---|
| Fabric | 92% polyester/8% spandex |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Midweight |
| Inseam (in.) | 29.5 inches |
| Gender | Women's |
| Sustainability | From a Climate Label Certified brand |
| 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 |
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.
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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Briarsmoke heatherrrrr, I LOVE this color & this fabric. Perfect for snowboarding! PLEAASE PLEASE please make a CAPRI length version!! Snowboarding socks plus a full length base layer isn’t a good combo. Especially as a type 1 diabetic, I have to look after my lower limbs carefully. I can wear a small or medium but go for the smalls since they can get stretched out and you want a base layer to be tight to wick away sweat! I’m 64” tall (these bunch around my ankles a little) 135lbs, 27” waist, 41” hips. These babies stretttch. Again... please make a capri length? I’m considering cutting one of my pairs of these to hit right below my knee. Also, allowing photo reviews would be a game changer
Boy are these tights dreamy! I received them a few days ago and have since been changing into them everyday after work. I bought them as a base layer for an upcoming backpacking trip in chilly temps so have yet to test them in the wild. But they’re incredibly comfy and warm, and they don’t require constant adjustment like most bottoms for me due to having a very pear shaped bod. Usually there’s an awkward tugging at the knees, or a sliding down from the waist, but not with these bad boys! I’m 5’7”, 155 lb, 28” waist, 40” hips; typically wear a size 8 in jeans, and the Medium is perfection. I’ll definitely be getting these in blue, too, once the next member coupon comes out!
Kept me warm and comfortable while hiking in snow in Glacier N.P. and Banff. Felt really good next to my skin and fit just right, not at all bulky under clothing. I'm older and my waist has expanded with my age, but the waistband of these tights did not bind or roll. Did not limit range of motion at all, nor did they sag or bag. Every problem I've ever had with tights/leggings has been solved thanks to REI. Will definitely purchase this product again.
I've been wearing merino baselayers since the 90s, way before it was a "thing"... But I've got to say that these are actually my all time favorite baselayer, especially for on the mountain. I've been losing weight (well, losing fat and gaining muscle) so am replacing my size medium bottoms with a size small. That said, they have held up amazingly well especially conidering how often they've been worn and washed over the past few seasons! My tops are all going strong, with no noticeable difference between the 3 season old tops and brand new size small bottoms. These are pretty much baselayer perfection... PLEASE don't ever change them!
i don't usually leave reviews but i am really happy with this purchase. they're SO SOFT and stretchy. i haven't tested them outside or over time yet, but the fit is great. i'm 5'7 and ~140lbs and i have very long legs. the medium is perfect fit for me. they're slightly baggy around the crotch which might not be for everyone, but i'd prefer that to them being too tight because i get annoyed wearing tight leggings for too long. a small would fit, but i'd prefer the range of motion from the medium. they're long enough for my long legs which is rare! i'm really happy with this purchase and based on other reviews excited for how warm everyone says they are.
I love REI’s base layer top and bottoms. I tried on the Smartwool brand as well and it felt itchy and not very stretchy. The top and bottoms and silky soft and super comfortable. I would highly recommend. I’m normally a medium, sometimes a large and I ended up buying the top in a small and the bottoms in a medium. The bottoms I may have been able to wear a small in, as they’re a little large, but didn’t have any issues with them stretching out. I wore both for three days straight hunting in Wyoming in the spring and they did great, didn’t smell bad after wearing all day for three days without washing. I’m just under 6ft tall and weigh around 165lbs. I just wish they’d make this same product in a heavy weight.
I bought two pairs of this base layer for a recent ski strip, and they did not disappoint. I was almost too warm with this base layer and my insulated ski pants. On snowy/colder days, however, they were just right underneath my insulated ski pants. Very satisfied with the feel, stretch, function, and warmth. Would absolutely buy again, especially as someone who cannot do wool. These were reliable and true to fit. I am 5'9'' and 130lbs with a size SM. Long enough for once, too!
I am an XL/16 in everything. I am 5’8”. My bottom measurements are 36-41” waist (it varies!) and 46” hip. The waist elastic and length is the only part of this size that worked for me - there was way too much fabric everywhere else. These are made for people with much wider legs. I have the tops of the same material and they are stretchy - less fabric in a legging style would have worked here, and is what I was expecting as it’s supposed to be a base layer. It’s super baggy. At the REI store clearance rack there were half a dozen of these in XL and only XL (no other/smaller sizes), so I’m not the only one with this problem.
I work outdoors in New England and have tried multiple brands of base layers including many merino wool brands. These by far are the most comfortable fitting and the warmest. They regulate temperature really well. Some mornings it’s in the 40’s and transitions to the mid 60’s and I’m able to keep them on throughout the afternoon without dying in an inferno with multiple layers but they are still extremely warm in the lower temps. This is coming from someone who veers towards the cold side. The fit is super comfy and comes up to my belly button. I’m a size 8/10 135lbs 5’3” and the medium fits perfectly. It is a little long but all pants are for me. Please bring back more colors!!! I have 2 pairs and want to buy more but would like the colors they have in the tops.
This is the BEST bottoms base layer! Not scratchy like the REI lightweight ones or Smartwool’s. Very soft and kept me warm under snow pants while snowboarding. I’m 5’6” and 140lbs, athletic frame, and the small fits great. The waist elastic may be too tight for a different body frame, but I have wide hips/thick legs and a smaller waist and this is perfection. I wish there were more colors but whatevs, I’m gonna order a second pair anyways.