Base layers are an essential part of an outdoor clothing system since temperature and moisture management are key in both blazing heat and a blizzard. Check out our rundown of the best next-to-skin layers to quickly find your perfect pair.

Last updated: March 27, 2023

Quick Recommendations

Check out this quick list of our favorites if you’re in a hurry, or continue scrolling to see our full list with in-depth reviews.

• Best midweight wool base layer: Smartwool Classic Thermal Men’s / Women’s

• Best lightweight wool base layer: Smartwool Classic All-Season Men’s / Women’s

• Best synthetic base layer overall: Patagonia Capilene Midweight Men’s / Women’s

• Best budget base layer: REI Midweight Half Zip Men’s / Women’s

• Best sun shirt: Outdoor Research Echo Hoodie Men’s / Women’s

• Warmest base layer: Odlo Performance Wool Warm Men’s / Women’s

• Most affordable base layer: Helly Hansen Lifa Stripe Men’s / Women’s

• Best warm-weather base layer: Patagonia Capilene Cool Trail Men’s / Women’s

• Comfy, sweater-like base layer: Patagonia Capilene Air Hoody Men’s / Women’s

• Best backpacking sleepwear: REI Silk Men’s / Women’s

What’s Most Important to You in a Base Layer?

PRICE - You don’t have to spend a ton of money to get a great base layer, but warmer layers and those made with natural fibers do tend to cost more. Ideally, you’d have multiple base layer tops to suit different seasons, so be sure to consider the combined cost when planning your budget.

• Best mid-range base layers: Patagonia Capilene Midweight Men’s / Women’s, Smartwool Classic All-Season Men’s / Women’s & Outdoor Research Echo Hoodie Men’s / Women’s

• Best budget base layers: Helly Hansen Lifa Stripe Men’s / Women’s, REI Midweight Half Zip Men’s / Women’s, REI Silk Men’s / Women’s & Patagonia Capilene Cool Trail Men’s / Women’s

• Best high-end base layers: Smartwool Classic Thermal Men’s / Women’s, Odlo Performance Wool Warm Men’s / Women’s & Patagonia Capilene Air Hoody Men’s / Women’s

WARMTH - One of the biggest factors you should consider when choosing the right base layers is what type of weather you typically recreate in. We keep an option from each of these categories in our clothing rotation, so that we’re always prepared for any type of weather.

• Warmest base layers: Smartwool Classic Thermal Men’s / Women’s, Patagonia Capilene Midweight Men’s / Women’s, REI Midweight Half Zip Men’s / Women’s & Odlo Performance Wool Warm Men’s / Women’s

• Best base layers for temperatures above freezing: Smartwool Classic All-Season Men’s / Women’s, Helly Hansen Lifa Stripe Men’s / Women’s & Patagonia Capilene Air Hoody Men’s / Women’s

• Best base layers for sun protection/warm weather: Outdoor Research Echo Hoodie Men’s / Women’s & Patagonia Capilene Cool Trail Men’s / Women’s

WEIGHT - For most 3-season trips, we prefer lightweight base layers because they’re more comfortable to wear under other clothing. Lightweight layers also help keep weight low for backpacking trips, when you’ll be carrying them in your pack for most of the day to wear in camp at night

• Best ultralight base layers: Helly Hansen Lifa Stripe Men’s / Women’s, Outdoor Research Echo Hoodie Men’s / Women’s & REI Silk Men’s / Women’s

• Best lightweight base layers: Smartwool Classic All-Season Men’s / Women’s, Patagonia Capilene Midweight Men’s / Women’s, Patagonia Capilene Cool Trail Men’s / Women’s & Patagonia Capilene Air Hoody Men’s / Women’s

• Best heavy-duty base layers: Odlo Performance Wool Warm Men’s / Women’s, REI Midweight Half Zip Men’s / Women’s & Smartwool Classic Thermal Men’s / Women’s

MATERIAL - All of the base layers we recommend are breathable, moisture-wicking, and quick-drying, but each material has its forte. Wool is great for thermoregulation, breathability, and odor control. Synthetics aren’t as warm, but they dry quickly and tend to be a bit more durable and affordable. Silk base layers are super comfy but will absorb more moisture than others and are best used as sleep clothes or when you aren’t likely to sweat.

• Best wool base layers: Smartwool Classic Thermal Men’s / Women’s, Smartwool Classic All-Season Men’s / Women’s, Odlo Performance Wool Warm Men’s / Women’s & Icebreaker 200 Oasis Men’s / Women’s

• Best synthetic base layers: Patagonia Capilene Midweight Men’s / Women’s, REI Midweight Half Zip Men’s / Women’s & Helly Hansen Lifa Stripe Men’s / Women’s

• Best silk base layer: REI Silk Men’s / Women’s

BASE LAYER BOTTOMS - This guide focuses on base layer tops, but don't forget about your lower half! A pair of base layer bottoms is also an essential part of any outdoor clothing system.

• Best base layer bottoms: Patagonia Capilene Midweight Men’s / Women’s, Smartwool Classic Thermal Merino Men’s / Women’s, Odlo Performance Wool Warm Men’s / Women’s & REI Midweight Men’s / Women’s

Sortable Base Layer Comparison Table

Best Base Layers of 2023

Smartwool Classic Thermal & Classic All-Season

BEST WOOL BASE LAYER OVERALL

MSRP: $115 (Thermal) / $90 (All-Season)

WEIGHT (Men’s M): 10.3 oz. (Thermal) / 6.5 oz. (All-Season)

FABRIC/WEIGHT: Midweight merino wool (Thermal) & lightweight merino wool + nylon (All-Season)

PROS: Good value, excellent moisture wicking, warm when wet, breathable, odor-resistant, stylish enough to be worn on its own (250)

CONS: Can pill after washing, may hold onto lint and pet hair, not as durable as synthetics in the long run

BOTTOM LINE: Smartwool’s Classic Thermal Merino (men’s / women’s) and Classic All-Season Merino (men’s / women’s) base layers do an excellent job of wicking moisture. And since they’re wool, they don’t hold on to odors which is a real plus on multi-day trips. The Thermal weight is just the right thickness to help you thermoregulate in chilly fall and winter conditions, while the All-Season weight is lighter and more ideal for use in milder temperatures throughout the year. The Thermal top is available in a variety of styles, but we like the quarter-zip version best for neck and chest ventilation. Both the Classic Thermal and Classic All-Season base layers are high-quality and perform well, which has made them our go-tos for a long time.

Patagonia Capilene Midweight Crew

BEST SYNTHETIC BASE LAYER OVERALL

MSRP: $79

WEIGHT (Men’s M): 6.2 oz.

FABRIC/WEIGHT: Midweight polyester

PROS: Affordable, durable, very comfortable, excellent moisture wicking, easy to layer

CONS: Not as warm or odor resistant as wool

BOTTOM LINE: The Patagonia Capilene Midweight (men’s / women’s) is a durable and comfortable base layer top that’s quite the steal at its price point. We’ve used this top for multiple thru-hikes, and it’s still going strong nearly a decade later. Of all the synthetic materials we’ve used, Patagonia’s proprietary Capilene blend is the softest, stretchiest, and the best at wicking moisture. While it doesn’t trap heat quite as efficiently as some wool base layers, the Capilene Midweight top is still highly versatile and easy to layer. During shoulder seasons, we often hike in this shirt by itself since it’s breathable and provides just the right amount of insulation for temperatures above freezing.

REI Midweight 1/2 Zip

BEST BUDGET BASE LAYER

MSRP: $60

WEIGHT (Men’s M): 9.8 oz.

FABRIC/WEIGHT: Midweight polyester

PROS: Affordable, durable, warm, very comfortable, excellent moisture wicking, easy to layer, thumbholes

CONS: Not as odor resistant as wool, heavier than some

BOTTOM LINE: Sometimes you come across a budget option that performs just as well as higher end items, and that is certainly the case with REI’s Midweight Half Zip top (men’s / women’s). This base layer is warm, durable, and comfy against the skin, so it’s become a staple in our layering system.

The zipper allows you some control over your level of insulation, so it’s versatile for a good range of conditions. Since it’s on the heavy side compared to others, we tend to only take it out in colder temperatures when we know we’ll be wearing it for most of our time outside. That said, the weight is still reasonable for packing it as a just-in-case item if you’re the type that likes to have an extra layer for sleeping in on chilly nights.

This top is durable enough for many seasons of use, making the already small price tag even more appealing. If you’re in need of something warm and well built on a budget, this is your guy.

Outdoor Research Echo Hoodie

BEST SUN SHIRT

MSRP: $75

WEIGHT (Men’s M): 4 oz.

FABRIC/WEIGHT: Ultralight polyester

PROS: Ultralight, exceptionally comfortable, UPF 15 sun protection, highly breathable, thumb holes

CONS: Not as durable as some, holds odor

BOTTOM LINE: The Outdoor Research Echo Hoodie (men’s / women’s) is one of the most comfortable base layer tops for summer conditions thanks to the light and airy fabric. It provides great moisture wicking on warm-weather days and reliable sun protection for hikes in high alpine country. And we love that it has a hood and thumb holes for extra head, wrist, and hand coverage. The fabric is thinner and a little more delicate than some others, but it should hold up for years if treated with care. Since the Echo Hoodie is ultralight, it’s perfect for protecting your skin on summer backpacking trips.

Odlo Performance Wool Warm w/ Facemask

WARMEST BASE LAYER

MSRP: $115

WEIGHT (Men’s M): 9.5 oz.

FABRIC/WEIGHT: Midweight wool/ polyester/nylon blend

PROS: Very warm, built-in face mask, durable, odor-resistant, easy to layer 

CONS: Not as versatile, heavier than others, tight fit may not appeal to some

BOTTOM LINE: Odlo’s Performance Wool Warm top (men’s / women’s) is uniquely designed with a balaclava-style hood to keep you warm and protected in the coldest conditions. The slim fit and seamless design of this top make it easy to layer and especially comfortable when worn under a backpack. The blend of merino wool and polyester materials offers the best of both worlds for breathability and odor control, so you can wear this layer for multiple days between washes. Because the Natural+Kinship is so warm, it’s not quite as versatile as many of the other shirts on our list, but when it’s cold out it’s pretty hard to beat.

Helly Hansen Lifa Stripe Crew

MOST AFFORDABLE BASE LAYER

MSRP: $45

WEIGHT (Men’s M): 4.8 oz.

FABRIC/WEIGHT: Lightweight polypropylene

PROS: Affordable, quick-drying, excellent moisture wicking, easy to layer, breathable

CONS: Not as versatile as some others, not as warm as others

BOTTOM LINE: If you’re on a budget, the Helly Hansen Lifa Stripe Crew (men’s / women’s) is an affordable option that doesn’t skimp on performance. Helly Hansen’s proprietary Lifa Dry material excels at moisture wicking and dries very quickly, so it’s a great choice for high-output activities. This base layer isn’t as warm as some others on our list, but the fit and flatlock seams make it comfortable for layering under other clothing. It’s also designed with flat, fitted cuffs that work nicely under gloves. We love the Lifa Crew for snowsports and backpacking since it has just the right amount of insulation for active days.

Patagonia Capilene Cool Trail

BEST WARM-WEATHER BASE LAYER

MSRP: $55

WEIGHT (Men’s M): 5.5 oz.

FABRIC/WEIGHT: Ultralight polyester

PROS: Affordable, soft, highly breathable, quick-drying, excellent moisture wicking

CONS: Not as odor resistant as wool, not insulative

BOTTOM LINE: Base layers aren’t just for keeping you warm; the Patagonia Capilene Cool Trail (men’s / women’s) actively helps cool you down. The material is highly breathable and evaporates moisture fast, so it’s perfect for vigorous hikes and warm, sunny conditions. This shirt feels like cotton, so it’s excellent for those with sensitive skin. But it performs like polyester to meet the demands of high-output outdoor activities. The Capilene Cool Trail shirt is also available in short sleeve (men’s / women’s).

Patagonia Capilene Air Hoody

COMFY, SWEATER-LIKE BASE LAYER

MSRP: $159

WEIGHT (Men’s M): 7.2 oz.

FABRIC/WEIGHT: Lightweight wool/polyester blend

PROS: Good warmth-to-weight, breathable, comfortable, hooded, stylish enough to be worn as a standalone sweater, odor-resistant

CONS: Expensive, can pill after washing, holds onto lint and pet hair, hood/mock neck makes it slightly less easy to layer

BOTTOM LINE: The Patagonia Capilene Air Hoody (men’s / women’s) is one of the more stylish tops on our list, which makes it good for wearing as a standalone sweater. The material is a blend of merino wool and Patagonia’s synthetic Capilene for an outstanding balance of breathability, durability, and odor control. The hood fits nicely, and we love that the high collar keeps heat in and drafts out. Because it’s a little bulky, the Capilene Air Hoody isn’t our first choice for backpacking, but it’s great for everyday wear and casual adventures when you want a touch of style as well as performance.

REI Silk Base Top

BEST BACKPACKING SLEEPWEAR

MSRP: $55

WEIGHT (Men’s M): 2.8 oz.

FABRIC/WEIGHT: Ultralight silk

PROS: Very comfortable, excellent warmth-to-weight ratio, ultralight, hypoallergenic, easy to layer

CONS: Not as versatile, not as durable as others, requires extra care when washing, sheer

BOTTOM LINE: If comfort and low weight are your main priorities, the REI Silk base layers (men’s / women’s) are an excellent option. They’re ultralight, luxuriously soft, and thin for easy layering. They also pack down ridiculously small when not in use. Silk has the best warmth-to-weight ratio of any base layer material, so this top and bottom (men’s / women’s) is an excellent first step in a toasty layering system. That said, the fabric is quite sheer, so this set is impractical to wear on its own. We typically reserve these layers for sleep clothes in camp or as part of a layering system on cold-weather trips.

Honorable Mentions

The following base layers didn’t make our final list, but they’ve still got a lot of good things going for them. You never know, one of these base layers might be perfect for you:

• Icebreaker 200 Oasis Crewe (men’s / women’s) - This high-quality wool top is very similar to our top pick, Smartwool Classic Thermal (men’s / women’s), but it’s slightly less breathable which gave the edge to Smartwool. That said, the Oasis Crewe is a bit softer against the skin so we still think it’s a great choice for low-output activities when you’re not at risk of overheating.

• Ortovox 185 Rock N Wool (men’s / women’s) - This wool top features a stylish design and feels softer than other wool base layers, but we found the seam at the elbows to be irritating after prolonged wear.

Best Base Layer Bottoms

• Best base layer bottoms overall: Patagonia Capilene Midweight (Men’s / Women’s) - We’ve had the same pair of Patagonia’s Capilene Midweights for years, and they’re showing very few signs of wear. We find the level of warmth they provide to be appropriate for most of the year, and their athletic fit makes them easy to layer.

• Best warm base layer bottoms: Smartwool Classic Thermal Merino (Men’s / Women’s) - These bottoms are our go-tos for winter and high-alpine adventures when temperatures dip to freezing and below. They're the most heat efficient bottoms on our list, and they’re the best at repelling odor after multiple days of wear on the trail.

• Very comfortable & warm base layer bottoms: Odlo Performance Wool Warm (men’s / women’s) - These are some of the best warm base layer bottoms for backpacking. They’re very form-fitting and the waistband lays super flat, so they’re very comfortable for layering and under backpack hip belts.

• Best budget base layer bottoms: REI Midweight (Men’s / Women’s) - If you’re on a budget, REI’s Midweight bottoms are a great choice. They have a flat waistband that lays comfortably under hiking pants and hip belts. These synthetic layers will keep you warm down to around freezing, so they’re good for backpacking in shoulder seasons.

• Best sleep layer: REI Silk (Men’s / Women’s) - We like sleeping in silk base layers because they’re soft and cozy, and they help to keep our sleeping bag clean from days of dirt and sweat on the trail. And since they’re ultralight, they hardly add any weight to our pack.

Critical Base Layer Considerations

TIPS FOR LAYERING - Finding the perfect outdoor clothing layering system ultimately comes down to personal preference and the conditions you’re in. Check out our Hiking Clothing 101 post for some great tips to help find what works for you.

MATERIAL - The material a base layer is made from can be a good indicator of how it will perform in various conditions. Below we’ll detail some pros and cons of the most common base layer materials.

• Wool - Wool tends to be more expensive than synthetic base layers, but it also has the best balance of heat efficiency, odor control, and moisture wicking capability. Because wool is so breathable, it’s easier to regulate our body temperature during high-output activities. Wool layers may not last as long as synthetic ones and they tend to pill after washing and hold onto lint and pet hair. That said, if you use our technical fabric care tips below, you should still get plenty of use out of your wool clothing.

• Polyester - Polyester clothing is durable, quick-drying,, and typically lighter weight than wool. We love synthetic shirts for their excellent moisture wicking capabilities and the soft feel against the skin. Synthetic layers don’t insulate as well as wool and they can actually sap a lot of your heat if they get wet. Still, they’re much easier to care for and shouldn’t need to be replaced for many years. Patagonia’s Capilene layers are our favorite synthetic shirts.

• Silk - Silk is highly packable and has an excellent warmth-to-weight ratio. This ultralight material dries quickly and is very durable for the weight, but it does require extra special care to maintain. Because of the delicate nature of this material, we tend to use silk base layers for sleep clothes rather than on the trail. The soft texture is super comfy, and wearing a base layer inside our sleeping bag protects it from accumulating trail grime.

CARING FOR TECHNICAL FABRICS - Technical fabrics require a little special care to keep them performing their best. Always follow the washing directions on the tags carefully, but here are some general tips:

• Use a front loading washer - The agitator in a top loading washer can be hard on seams and can snag zippers or drawstrings. Make sure you zip all the zippers and tie the drawstrings before washing to prevent wear and tear.

• Use a technical fabric wash - We recommend Nikwax Tech Wash or Woolite for washing any technical fabrics because these solutions won’t leave fragrances or residue on your clothing.

• Only wash when you really need to - A lot of technical fabrics are designed to be antimicrobial and shouldn’t hold odors. Hiking clothing doesn’t necessarily need to be washed after every use.

• Don’t use fabric softener or dryer sheets - Fabric softener and dryer sheets can deposit residue on the fabric and affect the performance negatively.

• Hang dry when possible - Heat and agitation in the dryer can damage technical fabrics so it’s best to lay them flat or hang them on a line to dry naturally. 

Need More Gear Advice?

If you liked this list, you’ll love the CleverHiker Gear Guide where we test and recommend tons of outdoor adventure gear from a variety of categories. here are some links to popular articles:

• 10 Best Hiking Shoes

• 10 Best Backpacking Tents

• 10 Best Sleeping Bags

• 10 Best Sleeping Pads

• 10 Best Backpacking Packs

• 10 Best Backpacking Stoves

• CleverHiker Top Gear Picks

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• Our choices are completely independent and based on personal experience.

• We’ve logged over 10,000 trail miles and test outdoor gear for a living.

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• We constantly update our guides when new products launch.

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• We’re lifelong learners and we’re always open to constructive criticism. If you think we’ve missed a product or got something wrong, we’d love to hear your feedback.

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