If you need an outdoor sleeping bag that will perform well in any weather conditions, check this selection of the best lightweight synthetic sleeping bag from the best-known outdoor brands.

Usually, when people search for a sleeping bag to carry on the trail, then down-fill sleeping bags are in focus. This is normal in view of their weight and compressibility. But there may be situations when a synthetic sleeping bag would be more appropriate. This holds in particular for long tours in wet conditions during which a down fill might gradually lose its insulating property and become wet and heavy.

As you know, synthetic insulation preserves its properties even if it gets wet. It also dries faster than a down fill or a cotton fill. So this is why I have decided to make this list.

You have a variety of options here. This means i) double-wide and solo sleeping bags, and also ii) synthetic sleeping bags with a variety of temperature rating. Some of them are with a clever design so you can have several variants in one product.

If you are with a partner, then a double-wide sleeping bag can be a great option. Such a bag is both lighter and more compact than when you would use two separate solo sleeping bags. It can even be warmer because of two bodies in the bag.

My list of best lightweight synthetic sleeping bags

The sleeping bags in the list below are ordered by the weight from heavier to lighter:


You will realize that I have done my best to include very different designs, and this was on purpose.

I hope you will love the products I present below, I choose only the best that is on the market, those that I can fully recommend, and present them here in the site. Just a heads up that as an associate of Amazon and other sellers, I may earn some commission from qualifying purchases of products bought via links on this page, at no additional cost for you.

1. Big Agnes Sleepy Bear 35 Doublewide Sleeping Bag

Big Agnes Sleepy Bear 35 Doublewide Sleeping Bag.
Big Agnes Sleepy Bear 35 Doublewide Sleeping Bag.

As you realize from the picture, this is a double-wide sleeping bag. For its overall size and features, it is still reasonably light to be carried on the trail. The weight is 5 lb 10 oz (2.55 kg). If you think this is heavy, wait to see its all features.

The shoulder girth is 128 inches (325 cm) and it is slightly tapered so the foot girth is 106 inches (269 cm). So it can be described as semi-rectangular.

It comes with a sleeve for the pad, and you can use either a double wide 78 x 50 inches pad or two single pads 78 x 25 inches. It is great to have such a sleeve to keep the bag in place when you roll around inside it.

You have a multi-denier and hollow-core Fireline Core synthetic insulation. It provides loft, structure, and warmth even in dump and wet conditions. Note that it has a massive and warm hood with insulation.

The bag is with a soft-shell polyester ripstop fabric on top. Inside is a cozy polyester lining, and this is all with a PFC-free water-repellent finish. The official temperature rating is 35 F (2 C), so the bag is for three season use. It can be compressed to (L x D) 12 x 10.5 inches (30 x 27 cm). The length is such that it fits users of up to 78 inches (198 cm).

What I like:

  • The comfort.
  • Packed size.
  • Weight.

What I dislike:

  • Practically nothing.

2. Exped MegaSleep Duo 25 Sleeping Bag

Exped MegaSleep Duo 25 Sleeping Bag.
Exped MegaSleep Duo 25 Sleeping Bag.

This Exped MegaSleep Duo 25 Sleeping Bag is here because of its synthetic construction, but it is incredibly versatile. It could be described as a 4-in-1 bag.

  • It has 2 temperature ratings. The meaning is that the two halves are with two different temperature ratings, so you can use one or another as the top layer.
  • It is designed to be used as a double-wide and also as two solo sleeping bags.

Note that you can use those two halves as separate blankets as well. As for the temperature rating, one side is with a 42.8 F (6 C) rating, and the other side is 26.6 F (-3 C). So if you use any of the two halves as a solo pad, you will have two different ratings.

The bag is rectangular and without a hood. The fabric is a moderately durable 40D ripstop nylon, Oeko-Tex 100 certified. The liner is 40D nylon and it is also Oeko-Tex 100 certified. The insulation is a 100% polyester Texpedloft microfiber.

You have a 3D anti-snag draft tube along the full length of the zipper. There is also a central snap at the head end, this is to reduce drafts caused by your partner.

Here are some numbers. The weight is 64.2 oz (1820 g). The dimensions are 82.7 x 63 inches (210 x 160 cm). The packed size is very impressive, it measures (L x D) 11.8 x 7.1 inches (30 x 18 cm), but they do not include a compression sack, so to reduce it to such a size you will have to buy one.

What I like:

  • Versatility.
  • Comfort.
  • Great packed size.

What I dislike:

  • Not for cold weather.
  • No compression sack.

3. Big Agnes Lost Dog Sleeping Bag

Big Agnes Lost Dog Sleeping Bag.
Big Agnes Lost Dog Sleeping Bag.

Here you have a complete series with several sleeping bags of different temperature ratings, and they are all built in at least two sizes, regular (R) and long (L). So you have plenty of options to choose from, to fit your body size and the environment where you plan to use the bag.

The bags are with what they call the FireLine ECO Synthetic Insulation, and this is a 100% post-consumer recycled polyester. You have low-denier fibers, tightly woven and with high loft and compressibility. This material is with a high weight-to-warmth ratio.

The external shell is a nylon ripstop with a water repellent finish, and inside you have a polyester lining. These bags are also equipped with inner loops for extra layering. They come with a Flex Pad Sleeve design, a stretch construction that can accommodate multiple pad widths.

To get some idea about numbers, in the case of the Big Agnes Lost Dog 45 Degree Sleeping Bag you have the temperature rating of 45 F (7 C). Its weight for the two sizes is:

  • Weight:
    – R: 1 lb 12 oz (794 g).
    – L: 1 lb 15 oz (879 g).

The following numbers will also be useful to know:

  • Compressed bag size:
    – R: 6.5 x 5.5 inches (17 x 14 cm).
    – L: 6.5 x 6.5 inches (17 x 17 cm).
  • Girth (shoulders/hips/knees):
    – R: 69/60/49 inches (175/152/125 cm).
    – L: 72/63/52 inches (183/160/132 cm).

What I like:

  • Many options to choose from.
  • Pad sleeve.
  • Great compressed size.

What I dislike:

  • The weight, but this only for the versions for lower temperatures.

4. Big Agnes V Notch UL 40 Degree Sleeping Bag

Big Agnes V Notch UL 40 Degree Sleeping Bag.
Big Agnes V Notch UL 40 Degree Sleeping Bag.

This sleeping bag can be described as ultra-lightweight and ultra-packable. Thy build it in two sizes and the numbers are:

  • Weight:
    – R: 1 lb 8 oz (680 g).
    – L: 1 lb 9 oz (709 g).
  • Compressed size (L x D):
    – R: 5 x 6 inches (13 x 15 cm).
    – L: 5.5 x 6 inches (14 x 15 cm).

The two sizes are for users of 6 ft (183 cm) and 6 ft 6 in (198 cm), respectively. The temperature rating is 40 F (4.4 C) so this is a sleeping bag for 2.5 – 3 seasons. You have a high quality synthetic 80% recycled PrimaLoft Hi-Loft Ultra Silver insulation. It is among the best you will find.

The shell and lining fabric is DWR nylon ripstop. You have a two-way zipper, so you can open it independently from the bottom to have some ventilation. This is a 70 inches (178 cm) YKK #3 locking zipper.

The bag is mummy style and with an ergonomic footbox, you have interior loops for extra liners. The girth (chest/hips/knees) is 59/53/36 inches (150/135/91 cm) for the R size, and 62/56/39 inches (158/142/99 cm) for the L size.

What I like:

  • Incredible weight.
  • Very compact.
  • Quality materials.

What I dislike:

  • No compression sack.

Final thoughts

So although the list given here is relatively short, you still have plenty of options to find the best lightweight synthetic sleeping bag for you. As mentioned, some are just representatives of series of bags, and some are multi-functional with a several-in-one design.

If you know you will be camping in a cooler environment, then having a hood is a good idea. On the other hand, if you want a bag that can be fully unzipped and used also as a blanket, having a hood is not so great.

There are differences in the weight and packed size, so bear this in mind if you plan to carry the sleeping bag on the trail, or to transport it on a bicycle.

Editor’s Choice

I have decided to put forward the bag shown below because of its weight and packed size. But this is not the warmest option in the list, bear this in mind.

Ultralight & very compact quality sleeping bag
Big Agnes V Notch UL 40 Degree Sleeping Bag.

Product Name: Big Agnes V Notch UL 40 Degree Sleeping Bag

Product Description: This is a high quality product from one of the best-known brands.

Brand: Big Agnes

SKU: B08174F2CR

  • Features - 9/10
  • Design - 9/10
  • Quality & craftsmanship - 9.7/10


The overall rating of this sleeping bag is well-deserved Excellent.

User Review
0/10 (0 votes)

Please see a bit more about this sleeping bag in the video:

You might want also to read about best backpacking sleeping quilts. This is the lightest option to carry on the trail. But see also the list of very light best down rectangular sleeping bags.

Thank you for reading. Let me know if you have questions, there is a comment box below.

Similar Posts