Down vs. Synthetic Sleeping Bag

You may be getting ready for your first overnight outdoors. Or, you might be looking to upgrade your sleeping bag. Before even considering the brand or model, you need to decide whether you want a down or synthetic bag.

So, which one is the best type of sleeping bag?

Well, the answer is not as straightforward as you may think. Aside from the price, there are other features that you will have to evaluate. First, the warmth to weight ratio and packability is a significant factor that you should look into, especially if you like going on solo hiking trips.

Additionally, you will also need to consider a bag’s water resistance to ensure that you stay warm even during the rainy season. Breathability is also a consideration to ensure that you are always comfortable the entire night.

In this article, we have compared the features of each type to determine their strengths and weaknesses. Do not miss a quick list of our favorite sleeping bags as well!

Comparison Table

Down vs. synthetic is a popular debate among outdoor enthusiasts, especially when shopping for gears. While sleeping bags in either type come in different models and brands, they have unique strengths and trade-offs. Let’s look at the most common characteristics of sleeping bags and how they differ in down and synthetic insulation.

 Warmth to Weight RatioPackabilityWater ResistanceBreathabilityPrice
  • Provides better insulation and heat retention
  • Lightweight

    • Highly packable
    • Maintains its loft and heat insulation

      • Loses loft when wet
      • Loses its insulation capabilities

        • Effective traps and maintains heat
        • Can become too hot and uncomfortable

          • $200 and up

            • Needs more material to provide the same insulation
            • Relatively heavier

              • Not as packable as down as it uses more materials for insulation

                • Resists water easily
                • Does not lose its insulation even when wet

                  • Insulation is not as good as down
                  • Breathable and allows the body to regulate its temperature

                    • As low as $50

                    Down vs. Synthetic Sleeping Bag

                    Down versus synthetic sleeping bags is an endless debate among novice and experienced outdoor enthusiasts. Each type offers specific benefits and shortcomings. To help you decide which one fits your needs, let’s take a look at the key characteristics.

                    sleeping bag forest from lovemsshin
                    via @lovemsshin from Instagram

                    Warmth to Weight Ratio

                    Anyone who experienced at least one backpacking trip knows that a sleeping bag’s warmth to weight ratio is a valuable factor when considering a purchase. Without a doubt, down’s warmth to weight ratio is better than synthetic’s, which is evident in its superior fill-power.

                    Fill-power refers to the cubic inches an ounce of down can fill inside a laboratory container. It measures the fluffiness or loft of the down. Higher fill-power means a warmer bag. High quality down fill, especially goose down at around 800-fill power or above, provides ultimate protection against the cold while maintaining its lightweight characteristics.

                    Synthetic insulation is composed of polyester fibers, which are relatively heavier than natural down fibers. Furthermore, you need more synthetic insulation to achieve the same warmth as down fill insulation. This also affects the packability of the sleeping bag. The upside of synthetic sleeping bags is it is relatively more affordable than down sleeping bags.


                    Packability is directly related to the warmth to weight ratio of the sleeping bag. Also known as compressibility, a lightweight down sleeping bag can be compressed down to the size of a handbag. It can be compacted more tightly than a synthetic sleeping bag.

                    The fill-power, and in turn, the loftiness, indicates the packability of the bag. As mentioned in the last section, the higher the fill-power means, the more the material will compress. For example, mid-tier down fill range from 450 to 650 fill power, and high-end ones have as much as 900 fill power.

                    High-end synthetic sleeping bags are around this range as well. But, they usually cannot match the packability of down as they require more materials to provide warmth.

                    It should be noted that sleeping bags, whether they are down or synthetic, will lose their loftiness when kept compressed and stuffed for a long time. Most sleeping bags come with a stuff sack, which is great when backpacking. However, you should use a larger sack made of nylon or cotton during storage to allow the bag to expand.

                    sleeping bag pack from royal_pacific_trade_exped
                    via @royal_pacific_trade_exped on Instagram

                    Water Resistance

                    One of the biggest advantages of synthetic insulation is its ability to protect you from water. It can maintain its loft and insulating capabilities even when wet. That means it is an ideal option if you are expecting damp weather or a chance of rain.

                    On the other hand, down tends to soak up water. It clumps when it gets wet and loses its loft. At this point, it will lose most of its insulating capabilities.

                    However, it does not mean that down sleeping bags will perform poorly overall. A down sleeping bag will have an additional waterproof membrane in the shell. This protects the insulation, thereby minimizing the effects of water.


                    When shopping for a sleeping bag, breathability is often overlooked by novice hikers. While warmth is definitely a consideration, it does not guarantee a good night’s sleep.

                    Down is considered a very effective insulator. It traps your body heat and maintains it in the bag. Unless you are in a cold environment, it can get uncomfortable when you are bundled up.

                    On the other hand, a synthetic bag is not as good as a down bag when it comes to trapping heat in. However, this also means that your body can breathe more effectively. It allows your body to regulate its temperature, so you do not feel too hot or too cold.

                    Of course, there are various ways to increase comfort in a down or synthetic bag. You can partially open the zipper to let a bit of air in. Some bags even allow some form of ventilation in the foot area. If you get too cold, you can double up using a jacket or a thinner, secondary sleeping bag.

                    sleeping bag cabin from roughknives
                    via @roughknives on Instagram


                    For most hikers or campers, price is the deciding factor. There is a significant difference between the price of a down sleeping bag and a synthetic sleeping bag. Down is known to be expensive as the demand is pretty high, and the supply is low.

                    Typically, a decent goose down bag costs around $300. However, the price will vary depending on the supply in your location. Recently, manufacturers have begun offering duck down insulators, which are slightly more affordable at around $200.

                    On the other hand, synthetic bags are available at a wide range of prices. You can even find sleeping bags under $100. There are high-end synthetics especially new models that are designed to mimic the performance of a down sleeping bag but with relatively lower prices.

                    Our Favorite Down Sleeping Bags

                    Choosing the best sleeping bag can be a difficult task, especially when you are already thinking of investing in your gear. You want to maximize your budget and choose the sleeping bag that best fits your needs. Here are some of our favorites.

                    Western Mountaineering MegaLite

                    If you are looking for an all-around sleeping bag, then Western Mountaineering MegaLite is a great option for you. It packs down to just 6 x 12 inches (15.2 x 30.5 cm), which is perfect for solo backpackers. Only weighing 1 lb. 8 oz. (0.7 kg), it almost feels like nothing in your backpack.

                    However, it does not mean the bag itself is small. It features a spacious 64-inch (162.6-cm) shoulder that will fit most people. It tapers down to a 39-inch (99-cm) wide foot area, which ensures comfort without getting too suffocating.

                    The top-notch insulation is further supported by the full-length #5 YKK zipper that keeps the heat in. The top collar also provides comfort to the head area, especially during cold nights.

                    Kelty Cosmic 20

                    While most down sleeping bags are expensive, Kelty Cosmic 20 manages to balance price and decent features. It has a fill power of 600, which is achieved by mixing 83% of down insulation and 17% of synthetic fibers. While it does not have the same warmth to weight ratio, it performs better than 100% synthetic sleeping bags.

                    The trade-off is noticeable in its weight at 3 lbs. (1.4 kg) which is still acceptable for backpackers but not as light as other down bags. The included synthetic insulation also helps the bag maintain its loft. Furthermore, its DriDown treated down ensures comfort, even when it is raining.

                    The outer layer is made of 20D Nylon Taffeta shell, which further prevents and repels moisture buildup. Additionally, it comes with an anti-snag zipper with a draft tube that effectively keeps the cold air out.

                    Sierra Designs Cloud 20

                    Sierra Designs Cloud 20 incorporates clever design and functionalities that increase its comfort and usability. It features a zipperless technology that includes a fully integrated comforter. It also comes with insulated hand and shoulder pockets that mimic a bed when it comes to comfort.

                    The sleeping bag also includes a pad sleeve on the bag where you can put your sleeping pad. This ensures that you will not roll off your pad when sleeping. That means you can move freely without worrying about your pad.

                    It provides great weight to warmth ratio at 800 fill power. The DriDown treated down maintains its loft even during the rainy season. Additionally, it stays dry longer and dries faster, which makes it easy to maintain.

                    Our Favorite Synthetic Sleeping Bags

                    Synthetic sleeping bags are not only popular for their affordable price but for their ability to repel water. While they are not the most packable option, their durability makes up for the weight and stuff size. Here are some of our favorite synthetic sleeping bags.

                    Marmot Trestles 0

                    Marmot Trestles 0 is an ideal sleeping bag if you are looking for an option that will keep you warm during cold weather without breaking the bank. At a temperature rating of 0°F (-17.8°C), it is perfect for hiking trips during autumn or mild winter.

                    Because it is a synthetic bag, it is slightly heavier than a down fill bag at 4 lbs 9.8 oz (2.1 kg). It is also noticeable in the stuff sack size, which measures 9.5 x 21 Inches (24.1 x 53.3 cm). While not an ultralight option, it is an acceptable weight and size if you are planning on backpacking.

                    The shell is made of polyester to protect the interior from rain or moisture. The included zipper guard prevents it from snagging on the material. Furthermore, it also includes a vaulted foot box that provides comfort but enough room to move around.

                    The North Face Dolomite One Bag

                    The North Face Dolomite One Bag is a versatile sleeping bag for maximum comfort. It features the company’s patented 3-in-1 sleep system, which is made of three layers that you can customize. These layers can combine into various configurations to achieve temperature ratings of 15°F (-9.4°C), 30°F (-1.1°C), and 50°F (10°C).

                    It features a rectangular structure which is perfect if you want both comfort and space. The wrap-around zipper opens from the bottom to allow ventilation. It is also quite easy to get in and out of the sleeping bag.

                    Furthermore, it is made of 30% post-consumer recycled Heatseeker synthetic fill which offers great weight to warmth ratio. The outer shell is constructed using 50D Ciré Polyester Taffeta that effectively repels water. Combined with a fleece-lined mid-layer, it provides premium comfort.

                    Big Agnes Lost Dog (FireLine Eco)

                    The Big Agnes Lost Dog (FireLine Eco) is another great all-rounder for budget-conscious hikers. It includes a Flex Pad Sleeve that attaches to your sleeping bag. This creates an integrated sleep system that will keep your bag on your pad for the entire night.

                    The mummy design features a Streamlined Silhouette that includes a roomy shoulder area measuring 72 inches (182.8 cm) in width. It tapers down to a vaulted foot box that measures 52 inches (132.1 cm).

                    The head area includes clever construction as well, such as a fitted jacket style hood. The internal cinch control provides better warmth control. Also, the no-draft collar, wedge, and zipper baffles enhance comfort.


                    sleeping bag in tent

                    Down vs. synthetic sleeping bag is a never-ending debate among outdoor enthusiasts. At the end of the day, each type provides unique benefits and trade-offs.

                    Down insulation has a better warmth to weight ratio; that is why it is popular among experienced backpackers. It is highly packable and lightweight, which is ideal for long hiking trips. On the other hand, down sleeping bags are also known to be quite expensive due to limited supplies.

                    One of our favorite down sleeping bags is Western Mountaineering MegaLite. It is a great investment as it is ultralight and highly packable. Also, its spacious interior will fit most individuals without sacrificing its ability to retain heat.

                    Meanwhile, many backpackers also like synthetic sleeping bags due to its affordability. It also maintains its loft and insulation even when it gets wet. However, synthetic bags are slightly bulkier and heavier than down.

                    A great example of a good synthetic bag is Marmot Trestles 0. While it is affordable, it does not skimp on functionalities. It has a great temperature rating, comfy mummy-style construction, and extra features such as a stash pocket.

                    The perfect sleeping bag boils down to your needs and wants. Consider your outdoor activities, location, and weather condition aside from your budget. After all, having a great night’s sleep with nature is part of the experience.

                    down vs synthetic sleeping bag - pinterest