Fabric weight guide
Which merino weight is right for you?
GSM is grams per square metre — how much fabric there is, not a warmth rating. Every weight is the same soft 17.5-micron Australian merino: it wicks sweat before it turns cold, insulates when it is cold and ventilates when it is warm. Lighter fabric breathes and dries faster; heavier fabric holds more heat when you stop moving. Choose by season and by how hard you will be working.
Warm & hot weather · 60°F+ / 15°C+ — and high effort in any season
Best for: summer hiking, running, cycling, hot-climate travel, everyday tees and office wear; the next-to-skin layer under a 250 when you work hard in winter
Pick this if: you want a shirt that stays fresh for days, dries in an hour and keeps you cooler than cotton in the heat — or you simply run hot
Think twice if: you will mostly be standing still in the cold; on its own a lightweight layer has little insulation to offer
Shop 165 GSM →Cool to mild · 40–65°F / 5–18°C
Best for: spring and autumn as a standalone top, summer evenings, cool-morning hikes and commutes; winter as a base under a mid-layer
Pick this if: you want one merino layer that covers most of the year, or you are unsure between light and mid — this is where most people should start
Think twice if: you run cold and your winter is genuinely cold: go straight to 250
Shop 190 GSM →Cold · 20–45°F / −7–7°C — the classic winter base layer
Best for: skiing and snowboarding, winter hiking, cold-weather work, frosty autumn mornings; top-and-bottom sets so your legs are not the weak link
Pick this if: you run cold in fall, want the classic winter base layer, or spend active days below freezing under a shell
Think twice if: you overheat easily on hard uphill efforts — a 165 or 190 underneath, 250 over it, is the better system
Shop 250 GSM →Deep cold · below 25°F / −4°C — especially when you stop moving
Best for: ice fishing, hunting stands, camp at altitude, winter mornings spent waiting rather than walking, a house that never quite gets warm
Pick this if: warmth matters more than breathability, you are chronically cold, or your winter involves long spells standing still outdoors
Think twice if: you will be working hard — it is too warm for a sweaty climb, which is exactly the point
Shop 320 GSM →A base layer works by sitting close to the skin, where it can move moisture — loose is not more comfortable, just slower. Between sizes? Size down for a next-to-skin layer under a shell, size up to wear it on its own or over another layer. Merino stretches with wear and springs back after a wash. Heavier weight is not itchier: itch comes from coarse fibre, and every weight here is the same superfine merino.
Size guide
Size Guide
Our merino has a close, next-to-skin fit by design. If you are between sizes, stay true to size for base-layer use or size up for a more relaxed everyday fit. Free returns within 30 days, so ordering two sizes and sending one back is completely fine.
How to measure
Chest — around the fullest part of your chest, with the tape level under the arms.
Waist — around your natural waistline, with the tape comfortably loose.
Hips — around the fullest part of your hips and seat.
Inside leg — from the top of your inner thigh to your ankle bone.
Measure over light clothing, keeping the tape snug but not tight. Tap any chart below to open it full size.
Men's Base Layer Set
Need different sizes for the top and the bottoms? Build your own set →
Women's Base Layer Set
Need different sizes for the top and the bottoms? Build your own set →
Kids' Base Layer Set
Men's T-Shirt
Women's T-Shirt
Men's Long Sleeve
Same body measurements across 165, 190, 250 and 320gsm.
Women's Long Sleeve
Kids' Long Sleeve
Men's Long Johns
Women's Thermal Leggings
Kids' Thermal Leggings
Men's Half Zip
Women's Half Zip
Merino Wool Socks
Beanies, snoods and balaclavas
Still unsure which size to pick? Email info@merinotech.co.uk with your height, chest and waist and we will recommend a size. Free UK delivery over £49 and free returns within 30 days.
- Free shipping over $49.99
- 30-day easy returns
- Ships in 1–2 business days
Description
Women's Merino Pants
Experience ultimate comfort and performance with our Women’s Merino Pants — your new favourite everyday essential. Made from ultra-soft Merino wool, these pants naturally regulate temperature, keeping you warm in the cold and cool when it’s hot.
Merino’s superior breathability and moisture-wicking properties ensure you stay dry and fresh, while its odor-resistant fibres keep you feeling confident all day. Lightweight, elastic, and unbelievably soft, these pants move with you, not against you. Naturally antibacterial, anti-static, and UV-protective, they offer everything you need — comfort, function, and timeless eco-friendly design.
Care
Turn inside out. Machine wash cold on a gentle cycle with a wool-safe detergent. Do not bleach. Lay flat or hang to dry.
Shipping & returns
Free UK delivery on orders over £49. Ships in 1–2 business days. 30-day free returns on unworn items with tags.
Women's base layer pants
The bottom half of staying warm
A soft merino legging with a wide comfort waistband and flatlock seams. Wear under ski pants, jeans or hiking trousers — or on their own at home.
Size guide
Women's Pants 250
Fit
A close, next-to-skin fit made to sit smoothly under trousers, jeans and salopettes. Between sizes? Go by your waist measurement.
How to measure
- Chest – around the fullest part of your chest, tape level under the arms.
- Waist – around your natural waistline, tape comfortably loose.
- Hips – around the fullest part of your hips and seat.
- Inside leg – from the top of your inner thigh to your ankle bone.
Measure over light clothing and keep the tape snug but not tight. Still unsure? Email info@merinotech.co.uk with your height, chest and waist and we will recommend a size. Unworn items can be returned free within 30 days.
THE FABRIC
Why merino wool
Merino wool moves sweat away from your skin as vapour and lets it evaporate from the fabric, so you stay dry and comfortable whether you are hiking, commuting or skiing.
Merino fibres naturally resist the bacteria that cause odour, so you can wear a base layer for several days, on the trail or while travelling, and it still smells fresh.
Wool can absorb up to 30% of its weight in moisture without feeling wet. In damp British weather it keeps insulating where cotton and polyester leave you cold.
Merino absorbs UV radiation: our lightweight layers offer UPF 25 and the midweight and heavyweight options UPF 50+, handy on long days in the hills.
Merino wool is naturally hard to ignite and self-extinguishes without melting onto the skin, unlike synthetic base layers.
Merino is a natural, renewable and biodegradable fibre. Sheep grow a new fleece every year, and a worn-out merino garment breaks down instead of shedding plastic microfibres.
FAQ
Women's merino thermal leggings: FAQ
What is this 250gsm thermal leggings best for?
It is a midweight 250gsm merino layer, best for skiing, hiking and cold UK winters. Compare every weight in our merino weight guide.
Which sizes are in stock?
Available to order now: , XS, S, M, L, XL, XXL. Our merino is true to size and designed to sit close to the skin; see the size guide for measurements.
Is this thermal leggings warm enough for skiing?
Yes. 250gsm midweight merino under a ski jacket and trousers is the most popular choice for a ski holiday. Choose 320gsm if you feel the cold.
What are merino thermal leggings used for?
They are a base layer worn under trousers, ski salopettes or waterproofs to keep your legs warm and dry. Merino regulates temperature, so they stay comfortable when you move indoors or start working hard.
Which weight of merino leggings should I choose?
165gsm for mild days and active sports, 200gsm for cool everyday wear and layering, 250gsm midweight for most winter activities and skiing, and 320gsm heavyweight for very cold conditions.
Can I wear merino leggings under jeans or a skirt?
Yes. The fabric is smooth and the seams lie flat, so the leggings sit neatly under jeans, work trousers, dresses and skirts on cold days.
How should women's merino leggings fit?
Close-fitting without restricting movement, with a comfortable waistband. They are true to size; compare your waist and hip measurements with the size guide.
How do I wash merino leggings?
Inside out at 30°C or lower on a wool cycle with a wool-safe detergent, then dry flat or hanging. No tumble dryer and no fabric softener.
I’m 5’7”, 170 lbs and ordered a large. They had more room in the waist/hips. I could have sized down. I think they are easy to layer under pants for warmth. Great value!
I’m 5’7”, 170 lbs and ordered a large. They had more room in the waist/hips. I could have sized down. I think they are easy to layer under pants for warmth. Great value!
It’s hard to wear any other legging or pants since these arrived from merino tech. They are soft, comfortable and look perfectly acceptable to wear out with a longer top. I’m 62 years old, 5’6 and weigh 160ish. I ordered a large. I might try an extra large to see if it makes them more like sweat pants. A medium would likely fit like a traditional legging or base layer pant. I think I need a few more colours because otherwise I’m living in these black ones.
Finding the Merino Products top quality and extremely soft.
This is my favourite of any hoodie I've ever owned! Comfortable and looks nice than most
This is my favourite of any hoodie I've ever owned! Comfortable and looks nice than most
I bought 250 weight Women’s Pants, size S. I first want to be clear these are very soft and I can already tell they will keep me toasty warm. Warm and soft is the goal, so that is great! However the sizing is bit strange. I bought S because of other comments that suggested XS would be too tight in the waist. That was a good decision, as the following will prove. I am 4’11” and the pants are very long on me (I have to roll them up at least 4 inches). They are also a bit baggy along the whole length of the leg, whereas I was expecting something with a more legging-style fit. However despite the loose fit in the legs, the waistband is VERY tight! Too tight. And I weigh only 109 pounds. I am a small person. That super-tight waistband does not compute paired with the loose long legs of these pants. I thought about returning them but decided instead I will cut open the waistband and sew on an extra two inches of elastic to the waist, which should make them wearable.
I bought 250 weight Women’s Pants, size S. I first want to be clear these are very soft and I can already tell they will keep me toasty warm. Warm and soft is the goal, so that is great! However the sizing is bit strange. I bought S because of other comments that suggested XS would be too tight in the waist. That was a good decision, as the following will prove. I am 4’11” and the pants are very long on me (I have to roll them up at least 4 inches). They are also a bit baggy along the whole length of the leg, whereas I was expecting something with a more legging-style fit. However despite the loose fit in the legs, the waistband is VERY tight! Too tight. And I weigh only 109 pounds. I am a small person. That super-tight waistband does not compute paired with the loose long legs of these pants. I thought about returning them but decided instead I will cut open the waistband and sew on an extra two inches of elastic to the waist, which should make them wearable.
My wife's merino wear is nice but we had to get medium weight because heavy weight in the pullover styles are all sold out out. The same with some men's wear. So, I wont be purchasing anymore until stock levels are are back up.
My wife's merino wear is nice but we had to get medium weight because heavy weight in the pullover styles are all sold out out. The same with some men's wear. So, I wont be purchasing anymore until stock levels are are back up.
I’m enjoying my merino wool base layer pants so much. I wearing them as lounge pants while recovering from an injury. Very warm and cozy.
I’m enjoying my merino wool base layer pants so much. I wearing them as lounge pants while recovering from an injury. Very warm and cozy.
A well-made, warm product. They do pick up quite a bit of lint. The waist is just right, but really another inch or two would be more comfortable. The legs are slightly baggy at the bottom. I expected a more sleek fit. Seem to have washed well. Better price than a lot of alternatives online.
A well-made, warm product. They do pick up quite a bit of lint. The waist is just right, but really another inch or two would be more comfortable. The legs are slightly baggy at the bottom. I expected a more sleek fit. Seem to have washed well. Better price than a lot of alternatives online.
I am 5'10" and weigh 133. I ordered the large according to the size chart. When it arrived, it was too small. The waist is 14 1/2" flat = 29. I ordered an XL and sent them back.
The XL waist is 15 1/2" flat. 28" crotch to bottom. Waist to bottom is 40" ~ far different from what the size chart says. Also the waist to the crotch is 12" so for me it sits below my waist line. I highly recommend these leggings. They are warm and feel great. I bought a pair in 2022 but wore them out and needed another pair.
Very soft and comfortable. I wear them mostly as pajama pants and they keep me warm but not too warm. I like the way merino wool tempeture regulates. Will buy again when on sale.
I am 5'10" and weigh 133. I ordered the large according to the size chart. When it arrived, it was too small. The waist is 14 1/2" flat = 29. I ordered an XL and sent them back.
The XL waist is 15 1/2" flat. 28" crotch to bottom. Waist to bottom is 40" ~ far different from what the size chart says. Also the waist to the crotch is 12" so for me it sits below my waist line. I highly recommend these leggings. They are warm and feel great. I bought a pair in 2022 but wore them out and needed another pair.
Very soft and comfortable. I wear them mostly as pajama pants and they keep me warm but not too warm. I like the way merino wool tempeture regulates. Will buy again when on sale.
I bought the Merino pants 250 in black, it is a perfect fit for me and the quality is great. It definitely met my expectations!
I bought the Merino pants 250 in black, it is a perfect fit for me and the quality is great. It definitely met my expectations!
I’ve lost a fair amount of weight and now have the problem of getting warm. These do the trick. Wear them under a T-shirt or usually a sweater and I’m finally warm. Great product for a great price.
I’ve lost a fair amount of weight and now have the problem of getting warm. These do the trick. Wear them under a T-shirt or usually a sweater and I’m finally warm. Great product for a great price.
I have been living in my new 320 merino longjohns. I got another pair just so I could wash the first without freezing!
I also got a slightly lighter pair hopeful for warmer spring temperatures to come.
I have worn many different brands of merino and/or silk longjohns but these Merino Tech are by far the best!
I have been living in my new 320 merino longjohns. I got another pair just so I could wash the first without freezing!
I also got a slightly lighter pair hopeful for warmer spring temperatures to come.
I have worn many different brands of merino and/or silk longjohns but these Merino Tech are by far the best!
Way too long. I cannot even wear them. I should just return them.
Way too long. I cannot even wear them. I should just return them.
Women's Merino Pants 250 Black
Women's Merino Pants 250 Black