What down jackets should you consider in 2020?
Disclaimer: This guide is my initiative and isn’t requested by or paid for by any gear maker and I haven’t received compensation by anyone for it.
For other products, like sleeping bags and pads, there is a testing protocol in place to give you a good indication how warm the product is. If you want a sleeping bag that works down till slight frost you look at bags that have a comfort rating of 20f(-6c). Of course there are still a lot of variables left. Like how is the fit? Do you easily get drafts? And do you lose down on vital places while tossing and turning?
Still you’ve got a great starting point; compare the bags that are rated 20f and see which one is right for you. for down jackets this protocol doesn’t exist, and that is where this article comes in handy. I’ve been comparing key metrics of ultralight down jackets to see how they stack up, so it becomes easier to narrow down the right jacket and to expose those jackets that are terribly under filled for their weight. It also makes a distinction between 2, 3, and 4-season jackets.
The best in a weighted ranking
Out of ~70 Ultralight jackets that weigh less than 11oz(310gr) these are the best and worst contenders according to my weighted ranking. A combination of warmth, weight and price:
Warmth to weight ratio
The most important metric to calculate the score of a jacket is its warmth to weight ratio. What you usually want when backpacking is a warm jacket that weighs next to nothing. The warmth is calculated using three elements. First is the baffle construction method, then follows a combinations of the amount of down fill and the quality of the down. That last metric is called fill power. The better the down, the more loft it can generate for the same weight. This is a linear scale; so 1000fp down is double as warm as 500fp down.
The jackets in the data sheet use everything from 650fp down to 1000fp down and that is a big difference. If you combine construction method, fill weight and fill power you get a total warmth indication. If you then compare that warmth to the weight of a jacket you get the ‘warmth to weight’ rating. If we solely look at ‘warmth to weight’ the best scoring jackets have around 50% fill weight with 800fp to 950fp down and two of the three top scorers have a box baffle construction. At the bottom you see around 25% fill weight with 650fp to 800fp down.
Warmth per $ ratio
Not unimportant is the question: how much jacket do I get for my money.? Getting the best of the best is often an expensive affair and sometimes good is good enough. So in the weighted ranking I also look at the money aspect. This is calculated by combining the warmth to weight ratio and the total warmth (adding down is expensive) and divide that by the retail price. That way you can find the jackets that offer great value. Here are some of the jackets with the best and worst warmth per $ ratio.
The best 3-season jackets
It is immensely difficult to put a temperature rating on a down jacket. There are simply to many variables. But let’s say you mainly go out in standard three season temperatures. With low activity you need to be comfortable down to 30f(0c) below that; get in your sleeping bag. A combination of my own experience, fellow hikers and conversations with gear makers lead me to believe you need a warmth rating of at least 2500 for this if you combine it with a base and mid-layer. To put that into more comprehensible numbers that is 3oz of 850fp down in a jacket with sewn through baffles (which is the standard for ultralight jackets). For example the famous Mountain Hardwear Ghost Whisperer scores 2100 and wouldn’t be warm enough which is correct in my experience. So these are the jackets between 2500 – 4000 with the best warmth to weight ratio. This is of course an arbitrary cutoff point and a jacket slightly below or above that might still be best for you:
Remarkable in the 3-season category
The one that jumps out immediately is the Timmermade SUL Down Sweater 1.5. It is incredibly light while still being warmer than almost half of the top 10. It also manages to do that while still being affordable with $240. Possible trade-offs are that this is as minimal as a jacket can get. No pockets, no zipper, no hood. If you want a little more functionality the Cumulus Primelite Pullover is a good contender. Offering a chest pocket and half zipper and costing just $155, one of the cheapest jackets in this guide while still being able to provide high quality material and craftsmanship. On the warmer end we see the Malachowski Zion which is fully equipped with hand pockets a hoody and full zipper. But at almost 9oz you can get warmer jackets than this for about the same weight if you look in the 4-season category.
The best 2-season jackets
But what if you don’t need to go to freezing temperatures? You intend to take this jacket out in the summer and some beautiful spring and fall days. Let’s say 45f(7c) is the minimum temperature. Then you need at least 1500 warmth – or an equivalent of 1.75oz of 850fp down – but since there are still a lot of variables (body type, height, activity, humidity, wind) that might not be enough. So for the upper end of the scale we take a slight overlap with the 3-season jackets and pick 2750. In that case these are the jackets with the best warmth to weight ratio:
Remarkable in the 2-season category
There are a lot of good contenders here. Haglofs L.I.M Essens is worth mentioning because it offers a lot of functionality while still balancing weight and warmth. In the bottom right corner we see the Timmermade SUL Down Sweater .75 which weighs an incredible 4oz. That is lighter than most base layers while still being able to keep you warm at camp on a cold evening. At the upper end of warmth we again see the Cumulus Primelite Pullover. But it is important to note that due to the upper warmth limit I’ve set for the 2-season category we don’t see the Timmermade Sweater 1.5 here while it is both warmer and lighter. It is also interesting to see that the 2-season jackets with hood generally don't perform well here. It adds a lot of extra material while possibly not really necessary in relatively warm weather.
The best 4-season jackets
Now this is a difficult category. That is because 4-seasons possibly goes into very, very extreme temperatures. And for a maximum of 11 ounces these aren’t jackets that will get you to the top of Everest. For every degree colder it becomes you need exponentially more down to keep you warm. For 25f(-3c) you’d need at least 3500 warmth or 3.5oz of 850fp down while I would say that for 15f(-10c) we are already talking about 5.5oz of 850fp down in a box baffled design or a warmth score of about 6000. At those temperatures a sewn through design simply isn’t cutting it anymore. The more loft and down a jacket contains, the more efficient a box baffled design becomes. These are the Ultralight jackets that provide the best warmth to weight ratio in winter conditions:
Remarkable in the 4-season category
The amount of jackets to consider here is smaller than in the other two categories. But there are four jackets that really stand out. There are three jackets here with a box baffle which is superior to the commonly found sewn thru designs in avoiding cold spots. Those are the Goosefeet Gear Box, Nunata Shaka UL and Timmermade Box Chamber. These are also the warmest jackets available out of the ~70 jackets compared, and it shows that a true winter jacket almost requires this type of design. The GooseFeet Gear Box Jacket excels here with 60% of its weight being 950 fill power down. A sewn thru design that is worth considering here is also from GooseFeet Gear, the Pullover. And at just 8oz that is a jacket that might be considered for 3-season conditions though with its pullover design it might be too warm in summer.
A conversation with gear makers
I’ve made this comparison as a way to provide some support and guidance in the search for the right down jacket. But it is just me, working with whatever data is widely available and that means this guide isn’t flawless. And it certainly isn’t a review of all these jackets! To be able to see it from different perspectives I asked several gear makers for their reaction/view on the matter. These reactions aren’t redacted and every one I’ve received is published.
Dan from Timmermade:
There are 3 points I’d make to help with accuracy. First, when comparing hooded vs collar jackets, consider a hooded jacket might have 5-10% of it’s total fill weight in the hood and 5-10% less fill in the body than a jacket with the same fill weight and a collar. Second, consider sewn through baffle line frequency and chamber size. Each line is a cold spot and a narrower chamber allows less loft. This spacing doesn’t always change concurrently with fill weight. You can see jackets with 4″ spacing and the same fill weight as jackets with 2″ spacing. The one with 2″ spacing has double the cold spots and less loft. Third, carefully consider sizing. A medium with a straight fit might have 15-20% more area than a medium with a tapered fit. That means the fill weight is spread over 15% more area and any one section has 15% less fill in it. Alternatively, if one wanted to negate all of these variables, one could simply ask a manufacturer for the specs on any given chamber of a jacket. That way, it doesn’t matter if there is a hood/not or baggy fit/not. It’s the spec used in every part. For instance I could say “the average loft is 1.25″. The baffle spacing is 5″. The chamber fill weight is area x 1.5.” Maybe more complicated than most want but for the discerning customer who want’s real accuracy, this is what you want to use.
Ben from GooseFeet Gear:
In terms of feedback on the guide, I think you have covered the bases! It is incredibly difficult to properly compare jackets that have a myriad of different features and weights, and you’ve done a fantastic job!
What about heavier jackets? Or woman’s?
Of course there are a lot more down jackets available and these 70 don’t cover all people and neither do they cover all situations. Luckily the Reddit user Union__Jack has been making other data sheets based on the same calculations as I’ve made mine. You can find them here:
How everything is calculated
- ((1 + (Baffle design * ((Fill weight * Fill power) / 1000))) * (Fill weight * Fill power))
Perhaps the most interesting. How am I trying to find a ball park figure for how warm a jacket is? The easiest and clearest part is at the end of the calculation. You look at the amount of down a jacket has and multiply it by fill power. And since fill power is a linear scale (you could argue that higher fp down is more susceptible to moisture but that starts a whole other discussion) this works quite well. So 5oz of 500fp down gives us the same warmth as 2.5oz of 1000fp down both a score of 2500. But then we don’t take into account baffle design. Most Ultralight jackets have a sewn through design which means the inner and outer material are stitched together to create baffles. But those sewing lines create cold spots because there isn’t any down there. The solution to this is a box baffle design like the image below shows.
By adding verticle pieces of fabrics those cold bridges are practically eliminated. The colder the weather becomes and the more down you have, the bigger the effect of a box baffles design. That brings us to the first half of the calculation (1 + (Baffle design * ((Fill weight * Fill power) / 1000))). The number for Baffle design is 0.00 when it is sewn through and 0.065 when it is a box baffle. Now let’s take the previously mentioned fictional jacket with 2.5oz of 1000fp down. With a sewn through design it becomes: ((1 + (0.00 * ((2.5 * 1000) / 1000))) * (2.5 * 1000)) that becomes (1 + (0 * 2.5) * 2500) and that is 1 * 2500 = 2500. But let’s see what happens when we use a box baffle: ((1 + (0.065 * ((2.5 * 1000) / 1000))) * (2.5 * 1000)) that becomes (1 + (0.065 * 2.5) * 2500) ant that is 1.1625 * 2500 = 2906 or 16.25% warmer. For every 1000 of warmth gained from the down a box baffle design adds 6.5% of warmth. If we double the down – so 5oz of 1000fp – the sewn through design has a warmth score of 5000 while the box baffle scores 6625. More than 30% warmer with the same amount of down.
Warmth to weight
- (Total warmth / Weight)
This one is a lot easier than the total warmth. To get a feeling how well a jacket performs for its weight we divide the previously calculated warmth score by the weight of the jacket in ounces. So if we take a jacket with a warmth rating of 2250 weighing 7.5oz we get 2250 / 7.5 = 300 while a jacket with a warmth rating of 1750 weighing 4.5oz gets 1750 / 4.5 = 388. This is a very easy way to see how much warmth a jacket packs ounce for ounce. And the differences are huge! Our best scoring jacket packs almost 4.5x more warmth ounce for ounce then our worst scoring jacket.
Warmth per $
- (Total warmth + (Warmth for weight * 10)) / Price
Now this is a fun one. You could say that this score is totally arbitrary and made up by me. And it is! But it does provide a nice way to see what you get for your money. We take two important factors that drive the price for a jacket up, first being the total warmth. Box baffles, strong but ultralight materials and high quality down are expensive. So if you get a combination of those things for not too much money that is awesome. So I took both the total warmth and the warmth for weight rating. Added them up and divided it by the retail price to give you a warmth per $ number.
- ((Warmth for weight * 3) / 100) + (Warmth per $ / 15) – (Weight / 1,5) + 1
The Weighted ranking might be the most controversial. and certainly the most arbitrary, but I took three aspects. The warmth for weight being the most important, so that one has by far the biggest influence. Then comes the warmth per $, if two jackets have the same specifications the cheaper one is better, right? And last and most debatable is the total weight. The idea is that with a heavier jacket it is easier to achieve a high fill percentage because you don’t need to add that much more outer material to be able to add more fill. Getting a high fill percentage in a lighter jacket is more difficult thus should be awarded.