Kelvin Active Jacket
Kelvin Active Jacket
Kelvin Active Jacket
Kelvin Active Jacket
Kelvin Active Jacket
Kelvin Active Jacket
Kelvin Active Jacket
Kelvin Active Jacket

Kelvin Active Jacket

  • Big Game : Turkey : Optifade Subalpine
$289.00 $144.50
(24 Reviews)

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Soft, silent and breathable, the Kelvin Active knows no off-season. This jacket excels in the backcountry and delivers superior breathability during active pursuits. Constructed with 80g Polartec® Alpha insulation and a DWR-treated durable nylon face, this jacket is a quiet outer layer in mild conditions or as an insulating mid-layer under a shell when the temps drop.

Product ID: #30055

Sizing Guide

Jacket & Tops Sizing

Size Chest Sleeve
Small 36 - 38" 33"
Medium 39 - 41" 34"
Medium Tall 39 - 41" 36"
Large 42 - 45" 35"
Large Tall 42 - 45" 37"
X-Large 46 - 49" 36"
X-Large Tall 46 - 49" 38"
2XL 50 - 53" 37"
2XL Tall 50 - 53" 39"
3XL 54 - 57" 38"

Pant Sizing (Inches)

Size Waist Reg Tall
30 30" 31"
31 31" 31"
32 32" 31" 33"
33 33" 32" 34"
34 34" 32" 34"
35 35" 32" 34"
36 36" 33" 34.5"
37 37" 33" 34.5"
38 38" 33" 34.5"
40 40" 33"
42 42" 33"
44 44" 33"

Pant Sizing

Size Waist Reg Tall
Small 28 - 30" 31"
Medium 31 - 33" 31" 33"
Large 34 - 37" 32" 34"
X-Large 38 - 41" 32" 34"
2XL 42 - 45" 32" 34"
3XL 46 - 49" 32" 34"

Dakota Pant Sizing

Size Waist Reg Tall
30 31" 31"
32 33" 31" 33"
34 35" 32" 34"
36 37" 32" 34"
38 39" 32" 34"
40 41" 32"
42 43" 32"
44 45" 32"

Glove Sizing

Size Palm Circ Length
Medium 8 - 8.5" 7.5 - 8"
Large 9 - 9.5" 8.5 - 9"
X-Large 9.5 - 10" 9 - 9.5"
2XL 10 - 10.5" 9.5 - 10"

Gaiter Sizing

Size Calf Circ Boot Size
M/L 17.5" US 6-10"
L/XL 18.5" US 10-14"

How to Take
Your Measurements


    Bend your elbow and put your hand on your hip. Measure from the center of the back of your neck, along the shoulder and down the elbow to the wrist bone.


    Take measurement under armpits, around fullest part of chest and shoulder blades.


    Measure around where you normally wear your pants, keeping the tape measure a bit loose or putting one finger between your body and the tape measure.

  • 4. INSEAM

    In a standing position,measure from your crotch to where you want your pants to end, breaking at the top of the shoe in the front and just above the heel in the back.

  • 5. GLOVES

    With hand partially closed, measure over the knuckles, around the hand, excluding the thumb.

Fit Guide

SITKA Gear engineers gear with a specific Fit and intended end use in mind. These functional designs provide the user with authentic garments for the right situation.

Fit Descriptions

We can communicate our Fit descriptions in 3 different ways. Keep in mind that each garment will allow for layering in accordance to the garments place in a system and described Fit

  • P/F
  • S/F
  • E/F

    Designed for minimal layering. Whether an early season piece or already insulated this garment fits to prevent inefficiencies in heat retention caused by dead space.


    Designed to accommodate layering for more versatility from early to late season climates.


    Designed for maximum layering in the worst conditions. Cut roomier to accommodate additional layering underneath.

Back to Shopping
  • GORE™ OPTIFADE™ Concealment Subalpine is designed for stalking and ambushing ungulates from ground level in tree-covered and vegetated terrain.

  • Weight: 13.77 oz. // Size: L

  • Fabric: 20-Denier Nylon Ripstop Shell (40-Gram, 100% Nylon), Breathable Polyester Mesh Lining.

  • Insulation: 80 g/m2 Polartec® Alpha® Insulation.

  • Durable Water Repellent finish resists light precipitation and prevents the face fabric from wetting out.

  • Highly Breathable and Thermally Regulating: Polartec Alpha Active is a non-migrating lofted fleece insulation that offers superior breathability and moisture management.

  • Brushed Fleece Hand Zip Pockets and Interior Zip Chest Pocket: The zippered chest pocket secures your necessities and doubles as a stuff sack. Hand warmer pockets are lined with brushed fleece for added warmth.

  • Neck and Chin w/ Brushed Tricot Lining: The neck and chin are lined with a brushed tricot to prevent chafing and add warmth and comfort.

  • Polygiene® Odor Control Technology safely neutralizes odor caused from sweat.

  • Imported

Moisture Wicking
Product is Performance Fit, designed for minimal layering.



Why We Made This

We found nothing existed between a fleece layer and loft insulation that met the demands of active cold-weather pursuits. Our solution was to create a high-performance insulating mid-layer with superior breathability for active pursuits. Constructed with a DWR-treated durable nylon face, the Kelvin Active Hoody can be worn as an outer layer in mild conditions or as a breathable, insulating mid-layer in the late season.

Product Comments

24 Reviews
Write a Comment
Reviewed On 07/12/2022

This Jackets warmth to weight ratio is extremely impressive. I have had this jacket for over 2 years now and have had no issues with it as far as durability and wear goes. It works great for a midlayer or as an outer layer in mild temps. I frequently use this under my Jetstream Jacket with a base layer and rarely get cold. It moves moisture very well and dries fast. Overall, a really great micro puff style jacket with a wide range of uses.

Kurt B.
Reviewed On 04/18/2022

Great jacket! Does its job well, moves sweat well. I'm comfortable in a Core Lightweight with this while moving/working down to 0F/-18C. Face fabric is nice and slick making it easy to add layers once you're stopped. Dries very fast. I'm 5'10", 230lbs and the XL fits perfect. Bonus feature - horse hair does NOT stick to the face fabric. It's expensive by the time it makes its way to Canada, but should last a long time.

Reviewed On 04/15/2022

This jacket is awesome! I built my system around it. I have the core lightweight hoody as my base layer. On top of that is the heavyweight hoody. Then is the Kelvin Active Jacket. On top of that is the Kelvin Aerolite Jacket. A recent experience I had with the Kelvin Active Jacket was in Utah out scouting some public land. I was wearing a simple t-shirt and then this on top. I hiked 5 miles in 50 degree weather and didn't get hot one bit. My face was sweating but my upper body was perfectly dry. It is very breathable. The next morning it was 35 degrees out and I just had a thicker Carhartt underneath. I was just around camp. The wind was blowing around 20 mph and I stayed quite warm. This is the most versatile piece I own, if not the most versatile piece Sitka makes. If they made this in solid colors I would buy another one for everyday use.

Reviewed On 09/25/2021

I can't say enough good things about this jacket. It is my favorite and most used Sitka gear. I wore this on my early archery elk season hunt this year in the Pacific Northwest. I slept in it, I layered it in the cold mornings and peeled it off as the temperature rose; and then back on again when the temperature dropped near dusk. It layers nicely with the rest of my Sitka gear and even looks good with a pair of jeans.
This is my most versatile Sitka jacket and I wear it all the time. Great jacket and very comfortable.

Reviewed On 07/14/2021

I love this jacket. I am 6' 210Lbs and the XL has been perfect sizing. It's deceivingly warm for it' s weight. I've gotten away with wearing it with a vest in the wind and been very comfortable. It's quiet, durable and packs very nicely. It's in my pack on every outing.

Rob Thomas
Reviewed On 06/26/2021

Absolutely love this jacket. This past season brought some crazy weather. This is a great insulation layer. I wore it under my storefront jacket and I stayed extremely warm while moving around in the backcountry in the snow. I would have to say if you're hunting in some cold weather that this is an absolute must to add to your system.

Ryan Williams
Reviewed On 01/03/2021

This was my first Sitka jacket and I went round and round trying to decide what to buy. Eventually ended with this. I like it but its not windproof so I need a wind jacket, the packets are nice but I’m afraid to loose things as they aren't zippered. I would recommend the jetstream jacket instead.

L Williams
Reviewed On 11/02/2020

I wanted so much more out of this jacket for the price. While the fabric is nice, it is a flimsy, shapeless piece that doesn't work well as a layering piece or as an outer layer. It's too baggy to wear under a jacket and way way way too light to consider as even a mild-weather outer piece without lots of layers underneath.

Sizing: I wear medium in just about everything I've ever purchased, and this medium is WAY too big. I am 5'4" and 130 pounds. The sleeves are 1-2" too long and the armpits are ultra baggy with extra fabric. Perhaps this is for women with very large busts. I'm average and I don't need all that material. The jacket is also on the long side for a somewhat short person. In general, the medium is just really big and baggy for the average fit hiker.

Design flaws: The pockets are completely inaccessible when wearing a pack. I literally can't get anything in or out of the pockets with my pack on, which makes me crazy. The inside pocket zips the wrong way--from bottom to top--so that when you unzip it, your cell phone slides out.

Pluses: The cuffs are nice and stay put. The pattern is quality and I like the fabric feel--seems resistant to abrasion.

Main comment: This jacket isn't an expert at anything. Its designing was imprecise and I'm not sure what they were going for or why something this lightweight would be so pricey.

Reviewed On 11/01/2020

Great product! Very warm, layer-able, and quiet! I wore this as a mid layer during the 2020 Elk season. It was perfect! Cannot recommend enough. Successful hunt thanks in part to great gear from Sitka!

Reviewed On 10/15/2020

I wear this jacket to work everyday and have been extremely pleased with how the garment performs. I am a fly fishing guide based out of Central Washington and push all of my gear to the limit. This jacket works great as an outer layer over a long sleeve or over a long sleeve AND a light sweatshirt. The jacket regulates heat well, keeping me warm in a light breeze but not too warm when I am rowing. I start my day with a heavier jacket and quickly switch into my Kelvin Active Jacket as soon as I push off from the launch. I've been wearing this jacket for over a month without washing it (wow, that sounds kind of gross now that I type this out) and have no stink in the "pits." Two thumbs up for the Polygiene! I would recommend the Kelvin Active Jacket to those looking for a light puffy that they can wear on the move to provide extra insulation.

Lane Mccarty
Reviewed On 08/13/2020

This is an awesome jacket lightweight, warm, and pretty quiet. This is a jacket you will always have in your pack.

Ryan A
Reviewed On 07/23/2020

Awesome jacket! Super lightweight and packable. Best for hiking around on cold September mornings and drys fast if it catches moisture.

Bob Legasa
Reviewed On 05/22/2020

One of my favorite pieces from the Sitka Line. There's nothing more comforting than slipping this on or underneath your jacket when you've reached the top of the mountain and you've slowed down your pace. It keeps you plenty warm for those times where your sitting or have some cold winds blowing on those ridge tops. It's lightweight and compact enough that it's always in my backpack.

E Willett
Reviewed On 05/10/2020

I bought the Kelvin Active Jacket and pants for spring turkey hunting in the northeast and it has not disappointed. We were “blessed” with a spring snow this weekend with temps in the 30’s and with a simple base layer I was warm enough. The XL fits true, next time I would buy a tall for the extra sleeve length. I do wish the cuffs were Velcro or magnetic closure as I am not wild about elastic cuffs but that is me and does not take away from the quality. This is not my last Sitka purchase.

Reviewed On 10/03/2019

Fell in love with this jacket on my two-week Alaska hunt. Just such a great mid-layer piece, and wish I would have find it sooner!!! It's not overly heavy/thick, and with no hood, it is very non-obtrusive. The athletic fit is great, especially on the arms (specifically the forearms) as to not bunch up too much. Great to layer over LW Core Hoodie and under Kelvin vest or Stormfront during inclement weather for sure!

Carl Abrams
Reviewed On 10/26/2018

Love this jacket! I used the Kelvin Lite for years because most of my hunting doesn't involve bitter cold. While I had no complaints with the K Lite, the Kelvin Active improved on it. The fabric is nearly silent, it breathes well and the fit is great (the Tall version is the cat's meow for my frame). When I expect cool weather the Kelvin Active is either on my back or in my pack.

Reviewed On 09/16/2018

Awesome Jacket. super light and super warm, But doesn't overheat when you get to moving around

Joe Owens
Reviewed On 01/20/2018

Love the pattern and the design, very lightweight. But I think the sizing is a bit off. I'm 59", 170 pounds, and the medium fits so tight on my chest I can barely zip it. Also bought the mountain pants, and they are awesome.

Trevor Trehearne
Reviewed On 12/26/2017

Really lightweight but very warm nice fit. Except wish it was longer.

Reviewed On 12/24/2017

I want to start this review by saying I had very high expectations for this jacket. From what I had seen in videos and read this was supposed to be the ultimate insulation layer, keeps you warm when stationary, but breathes very well when active. Well upon receiving it the first thing I noticed was how lightweight/thin of a jacket it was this gave me my doubts. Then I had a chance to use it for a late season elk hunt in western Washington. 4 out of 4 stars! This did not disappoint at all! I put it on in the morning and never took it off. It was exactly what I was hoping for, can definitely feel the warmth when you're wearing it and is great under the Thunderhead jacket. I even wore it to sleep in for added warmth. But I never got too hot when wearing it solo or layered. Idk how they did it but it's great. The body is a little short but it was made this way so it isn't sticking out underneath other jackets when used as a layer. I'm 5'8" with athletic build and with Sitka performance fit I wear a large and this fit the same. Great jacket, I highly recommend it.

Reviewed On 11/13/2017

Just a regular dude here. The hype is real...Soft, quiet, drys quickly, and is lightweight. Makes a great pillow in the sleeping bag. It's almost like a really intense base layer in the sense that it's warm, but wicks away moisture. It's bizarre; no other jacket like it and I recommend you check it out.

Reviewed On 10/17/2017

Not sure how they do it. I have the Kelvin Lite, the Kelvin Ultra Down, and the Kelvin Active. All excellent pieces and all seem to be designed for something different. I didn't think it could get any better than the Kelvin Lite. Then the Kelvin Ultra Down came out. My absolute favorite piece. Being a little skeptical of their newest piece, the Kelvin Active jacket, I put it to the test. The previous pieces are mostly design for low activity to no activity. The Kelvin Active jacket somehow keeps you warm with low activity and vents heat during high activity without sweating. No clue how they do it but this jacket is a killer at have. Warmth without overheating.

Reviewed On 09/26/2017

This jacket is AWESOME! Was super excited about it when I tried it out at the Western Hunt Expo and it lived up to the hype. Wore it for two weeks while guiding wilderness hunts and it is probably my most favorite new piece of gear. Plenty warm as a stand alone outer layer even on cool mornings riding in on horse back and combined with decent rain gear, it's a perfect mid layer. Dries out quick and seems to help keep my base layer dried out as well. Going to be even better during the rifle seasons underneath my Jetstream jacket.

Jon Sica
Reviewed On 09/17/2017

This thing is awesome. You can go uphill all day, and never be too hot or too cold. Dries like a dream and makes a great pillow...what more could you ask?

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SITKA Gear - 07.26.2017

The Linguists

Few sounds in nature rival the bugle of a bull elk. Join nine-time World Elk Calling Champion Corey Jacobsen as he explores a hunting legacy with elk calling pioneers Larry D. Jones, Wayne Carlton, Rockie Jacobsen, and Will Primos.