Western Mountaineering Ultralite vs. Alpinlite

If you have the budget to buy the absolute best sleeping bag, you would surely end up on Western Mountaineering and Feathered Friends. Both of these companies produce the most premium sleeping bags you can’t go wrong with, and why should you? You are paying a hefty price.

The Western Mountaineering has two options, the Ultralite and the Alpinlite that are similarly specced. Choosing one of them is confusing for people because of how competitive they are even when both of these sleeping bags are from the same manufacturer.

To find out the details about the feature set both sleeping bags have and the differences between them, keep reading.

Western Mountaineering Ultralite

Western Mountaineering Ultralite
Weight: 1 lb. 13 oz.
Fill: 850+ down
Rated to: 20°F
Best use: Backpacking

The Ultralite is a premium offering by Western Mountaineering. With its lightweight design, the Ultralite stays true to its name. The premium quality down along with unique construction makes this bag extremely versatile and a treat to use.

Weight and Pack Size

The Ultralite sleeping bag does justice to its name by being extremely lightweight. The Ultralite weighs only 29 ounces for a size long. Now, being almost 2 lbs. may not be light to many people, but it is in context to its high performance in terms of warmth. For colder nights, the extra ounces make quite a difference. It is also worth noting that the Ultralite has one of the highest warmth-to-weight ratios.

But as the amount of insulation goes up, the pack size also goes up. The Ultralite is no exception. This sleeping bag has one of the largest pack sizes. But it should also be kept in mind that this bag also provides the highest warmth per liter. Using a compression sack, you can manage to squeeze this bag to a smaller size though.


In terms of comfort, the Ultralite is not as comfortable as the other offerings by Western Mountaineering have generous dimensions. The Ultralite has narrower dimensions which may make you feel cramped, especially, if you have a broader body structure. However, the dimensions are still similar to other standard mummy sleeping bags.

In terms of warmth, the Ultralite is one of the best performers you can find and it is one of the warmest 3-seasons bags. This sleeping bag features 16 oz. of premium 850+ power down which provides more warmth. This sleeping doesn’t receive a third-party EN temperature rating but it provides more warmth than bags with 20°F EN lower rating.

The warmth is further boosted by an excellent draft collar which can be closed in a way that it remains comfortable and seals the heat inside the bag. The draft collar the bag to be used in colder spring and fall conditions or higher altitudes adding to its versatility.

The versatility is further increased with the horizontal baffle construction of the bag. These horizontal baffles allow you to shift the insulation to the top and the underside. During cold nights, you can shift the insulation on top for more warmth and during warm conditions, shift the insulation to the side for access heat to escape. The shifting of the insulation is not an option with vertical baffles or synthetic insulation.

The Ultralite features a full-length zipper that can be used to vent out excess heat and also easy entry and exit from the bag. On the hand, the draft effectively prevents drafts to take away heat on colder nights. These features together allow the Ultralite to be comfortably used throughout a range of temperatures.


The Ultralite is an excellent bag that stays true to its name with its lightweight. It is a versatile sleeping bag that can be used in a range of weather conditions except for the wet owing to its down fill. But, this lightweight and versatile package comes with a steep price tag. That being said, the price is justified by its high performance.

What I like: Good warmth to weight ratio, premium loft, and legit draft collar

What I don’t: The hood closure is awkward and feels a little bulky

See the Western Mountaineering Ultralite

Western Mountaineering Alpinelite

Western Mountaineering Alpinelite
Weight: 1 lb. 14.4 oz.
Fill: 850 down
Rated to: 20°F
Best use: Backpacking

Just like the Ultralite, the Alpinelite is another premium offering by Western Mountaineering. It has the same premium quality down fill that is featured in the Ultralite with the same unique construction making it highly versatile. But unlike the Ultralite, the Alpinelite has generous dimensions and a bit of room to wiggle making it a lot more comfortable.

Weight and Pack Size

The Alpinlite comes filled with 19 oz. of down fill, which is 3 oz. more than that in the Ultralite. But despite having 3 oz. more fill than the Ultralite, the Alpinelite weighs only 2 oz. more with a total weight of 1lbs. 15 oz.

Just like the Ultralite, the Alpinlite doesn’t pack small and you would have to use a compression sack to pack the bag small. The stuff sack that comes with the Alpinlite is itself heavy. With its regular stuff sack, you would have a high volume packed sleeping bag which can cause you problems with storage in your backpack.


In terms of comfort, the Alpinelite is more comfortable than the Ultralite because of its wider dimensions making it roomier and comfier. It is a classic mummy bag with a bit of room to move inside. The wider dimensions are adequate for those who have a wider body structure and also allow you to stuff warmed socks in case of cold or some gear. Inside, the Alpinlite uses the same soft lining materials as in Ultralite giving a premium feel.

Just like the Ultralite, the Alpinelite is among the best performers in terms of warmth. The Alpinlite features 19oz. of 850+ premium power down fill. But having more down doesn’t make the Alpinlite warmer than the Ultralite because it has a larger surface area it needs to warm. But it is still as warm as the Ultralite which means it can be used for a lower temperature of 20°F. However, just like the Ultralite, the Alpinlite also doesn’t receive the third-party EN temperature rating.

The Alpinlite has the same premium draft collar as the Ultralite which is comfortable and also forms an effective seal to keep the warmth trapped inside the bag. The draft collar allows the Alpinlite to be used in colder conditions.

The Alpinlite also has the same horizontal baffle design as the Ultralite which allows you to shift the insulation. It helps you manage the warmth of the bag as down insulation under the body loses its insulation due to compression. During cold nights, you can shift the insulation on the top of the bag to gain maximum warmth and you can shift the insulation under yourself to minimize excess heat during hot nights. The horizontal baffles allow the bag to be used throughout a wide range of temperatures. The bag, again, has a full zipper that allows good ventilation and ease of entry and exit.


The Alpinlite is a sleeping bag just like the Ultralite with more room, insulation, and weight. But it costs about $45 more than the Ultralight due to its roomier dimensions and more down fill. The Alpinlite is similar to Ultralite in all other aspects and the two sleeping bags have the same feature set and performance figures.

What I like: Versatile, excellent loft, zippers don’t snag

What I don’t: Expensive, too warm for summer use, weak Velcro closure for draft collar

See the Western Mountaineering Alpinelite

Comparison Table

Temperature rating20°F20°F
Total weight1 lb. 13 oz.1 lb. 15 oz.
Fill weight16 oz. 19 oz.
Shoulder/foot girth59”/38”64”/39”
Full down collarYesYes
Full-length zipperYesYes
Best useUL BackpackingBackpacking

Which one is right for you?

There is no difference between the Western Mountaineering’s Alpinlite and Ultralite sleeping bags except that the Ultralite is a cut-down version of the Alpinlite. In the end, it comes down to the price you are willing to pay and your body structure. Everything else is the same. Both bags use the same materials and have the same features.

If you compare the two sleeping bags on price alone, which most of you would, then the Ultralite is the clear winner and you should get it. But is the Alpinlite worth the extra $45? I think it certainly is. Both of these bags aren’t cheap by any means and require you to pay a premium. While you would have many options at this price point, I would personally recommend the Alpinlite over the Ultralite. The Alpinlite has more space inside making it more comfortable. The Ultralite feels a bit cramped.

Surely, paying $45 more and carrying just 2 oz. extra isn’t that bad. However, you should choose the Ultralite if you are counting your ounces to keep things extremely lightweight. The Ultralite is also a good option if your body structure is considered small because then you would have wiggle room even with the cut-down dimensions. It will also save you 2 oz. and $45.