Down vs Synthetic Sleeping Bag – Which One is Right For You?

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Are you planning a camping trip or outdoor adventure and wondering whether to invest in a down vs synthetic sleeping bag?

Both types have their advantages and disadvantages, so it’s important to choose the right one for your needs.

In this article, we’ll compare the features of each type to help you make an informed decision. Whether you prioritize warmth, weight, or cost, we’ve got you covered.

Read on to find out which type of sleeping bag is best for you.

family sleeping in sleeping bags

The quest to find the perfect sleeping bag is every hiker’s goal. Finding the right sleeping bag involves several factors. Once determined, it becomes a treasured part of a backpacker’s outdoor sleep system.

The right sleeping bag provides both comfort and warmth for a good night’s rest. Proper insulation for weather conditions encountered during your adventure keeps your body temperature in check.

Sleeping bag insulation is vitally important for providing that warmth. It directly affects how cozy you remain amidst cold nighttime temperatures. As to what material is best for sleeping bag insulation, let the goose down vs. synthetic fiber battle begin.

Your body emits heat even when you are sleeping. One of the sleeping bag’s tasks is to contain that body heat. Loss of body heat while sleeping makes you cold. While some sleeping bags are sufficiently insulated to use alone, others require a sleeping bag liner for extra warmth.

A sleeping bag’s fill material determines to a great extent how good it is in keeping you warm, especially during winter camping. How that bag is constructed plays the other role. Cold spots are created if the fill material is allowed to shift around within the bag leaving areas with little to no insulation.

Terminology to Understand

Fill Power

Fill power is the measure of the loft or fluffiness of down products. The higher the fill power of an item, the warmer it is. A lighter weight sleeping bag with higher fill power provides more warmth than a heavy sleeping bag with a fill power of a lower limit.

Fill power isn’t the same as a temperature rating and should not be mixed up with it. Fill power ratings range from 300 to 950 and up. For high-quality down sleeping bags and insulated jackets, go for at least a 550 fill power rating.

Fill Weight

While fill power rates the quality and loftiness of the down, fill weight rates its quantity. How much fill does a sleeping bag have? If the down weight is 14 oz, the finished product has been filled with 14 oz of material.

Temperature Rating

The EN or ISO temperature rating on sleeping bags gives you an idea of  how warm the sleeping bag is. It typically provides both a comfort and lower limit temperature guide. Both EN and ISO ratings are essentially the same and apply to the average person.  However, temperature rating is mostly subjective since some people feel cold more than others.

How warm you sleep depends on other factors as well. Because your sleep system includes a sleeping pad as well as sleep clothing, the temperature rating of your sleeping bag is affected. An insulated sleeping pad will add additional warmth, as will warm sleep clothing. Temperature ratings are useful when you compare different sleeping bags. The EN and ISO ratings are now standardized and give a fairly accurate thermal efficiency across various manufacturers.

Warmth to Weight Ratio

The warmth-to-weight ratio is the measurement to check how effective the insulation material of a certain product is in relation to the weather conditions. Down products always offer the best warmth-to-weight ratio, making them an excellent option for high altitude and cold weather camping.

Down vs Synthetic Sleeping Bags: Pros and Cons

There are two types of sleeping bag insulation: down and synthetic. Down is known as natural insulation, while synthetic is made from a synthetic material created in the lab.

An additional type of insulation has been added through the years as technology has become more advanced. Some manufacturers combine the capabilities of both down and synthetic fibers to create a hybrid construction. A sleeping bag with a down/synthetic blend enjoys the advantages of both insulations while minimizing its cons.

Down Insulation

Down insulation traps warm air next to your body and keeps you warm even during extreme cold. Down should not be confused with the exterior feathers of waterfowl. In truth, it is the plumage or a layer of ultra-fine feathers underneath the exterior ones that we visibly see.

Typically, the best down is sourced from geese. But many brands nowadays use duck down to cut manufacturing costs. Rest assured, however, that both goose down and duck down have exemplary warming qualities that keep you safe from the frigid cold.

A sleeping bag filled with down has a better warmth-to-weight ratio than synthetic. A down filled sleeping bag does not need as much fill material since it lofts more. The additional loft traps warm air next to the body, providing a barrier to the cold outside air. 

Down has better fill power, making the sleeping bag warmer without compromising its compressibility and weight. A goose down sleeping bag with the same temperature rating as a synthetic sleeping bag insulation will always be lighter and pack smaller.

That being said, a down sleeping bag is next to useless if it gets wet. The Geez knows this firsthand. On a backpacking trip in the Golden Trout Wilderness some thirty years ago. I pitched my tent during an afternoon thunderstorm. It just so happened that back end of my tent landed in a stream that wasn’t there when it started raining. The footbox on my North Face sleeping bag got soaked. I spent the rest on my trip curled up in the dry top portion of my bag just to stay warm.


  • Best warmth-to-weight ratio
  • Durable that can last for many years
  • Highly compressible and packable
  • Lightweight
  • Great for extreme cold but dry weather


  • Does not do well in wet conditions
  • More expensive than a synthetic sleeping bag
  • Requires extra care in cleaning

Synthetic Sleeping Bag

Synthetic insulation is also popular for both sleeping bags and jackets. Synthetic jackets and sleeping bags are filled with lab-created polyester fibers and other synthetic materials. Synthetic fiber is quick drying whereas when down gets wet it takes forever to dry out. Synthetic insulation retains much of its insulating ability even when wet and in humid weather.

The polyester fibers that insulate sleeping bags are hypoallergenic. This makes synthetic insulation a good option for people hypersensitive to feathers.

There are many types of synthetic insulation. There are short staple fibers, continuous filament, and hollow-fiber insulations. These sleeping bag insulations differ from one another but still provide warmth to protect you from the cold.

Short staple fibers minimize heat loss by densely packing short strands of small denier filaments. This results in softer, more flexible and highly compressible products similar to goose down items.

However, products made from short staple fibers are not as durable. The insulation in these products also moves around, creating cold spots.

Meanwhile, continuous-filament insulations have strong, durable and lofty fill that prevent cold spots. However, the downside is that they feel stiff on the skin and cannot be compressed well, leading to bulky packing.

Synthetic insulation differs by type and adds to a buyer’s confusion when purchasing a sleeping bag. The most common types of synthetic insulation used in sleeping bags are Thermolite, Hollofil and its derivative, PolarGuard and its derivative, and Quallofil.

These different types have their own advantages and disadvantages depending on what you want and how much your budget is.


  • Water-resistant
  • Dries quickly
  • Provides insulation even when wet
  • Hypoallergenic
  • Less expensive
  • Easy to care for


  • Heavier and bulky
  • Not as warm as down
  • Less durable
  • Insulating power decreases over time

Down/Synthetic Blends

Thanks to technological advancements, a mixture of down and synthetic has been created. This blend of down and synthetic materials combines the advantages of down and synthetic fill while minimizing each of their pitfalls.

Sleeping bags with this hybrid construction usually blend the materials throughout the sleeping bag. But, others use down on the upper part of the sleeping bag while using synthetic insulation for the bottom of the bag. Down and synthetic blends are also used in other outdoor gear, such as winter jackets.


  • Less expensive than pure down
  • Resists water more than pure down
  • Lighter weight than pure synthetic
  • More compressible than pure synthetic
  • Mid-range price


  • Not as compressible as pure down
  • Heavier and bulkier than pure down
  • Not as water resistant as pure synthetic

Down vs Synthetic Sleeping Bag Battle

hikers in two different types of sleeping bags down vs synthetic sleeping bag

The battle between down vs synthetic sleeping bags has been a continuing saga over the years. Nothing is better than the other because it depends on what you need during your camping trips. As a matter of fact, you might even need to have both to choose the appropriate gear to bring on your outdoor adventure.

Price: Less Expensive Is Synthetic, but Down Is a Wise Investment

Synthetic sleeping bags are more affordable. High-quality synthetic bags may cost the same or even less than lower-end down products.

This is because synthetic fiber can be conveniently made within a manufacturing facility while down must be naturally and ethically sourced from waterfowl. The process of sourcing alone does not come cheap.

However, if you want a good investment to last, buying a down sleeping bag will benefit you in the long term. It lasts longer and is more durable than synthetic ones. Hence, you don’t need to buy a sleeping bag as often as you would with synthetic.

Don’t waste your money on low-quality down sleeping bags as the down tends to clump, leaving cold spots in the bag. In addition, they tend to lose feathers through the fabric shell on the bag. The craftsmanship of cheaper low-quality down sleeping bags is sadly lacking. You might find yourself regretting your purchase.

If you are in the market for a quality product, choose a down sleeping bag from a reliable manufacturer. It will last you for many years.

Water-Resistance: Synthetic Wins

As far as water resistance is concerned, synthetic easily wins this round. Synthetic sleeping bags are known to be extremely water resistant.

It does not compromise your comfort and warmth when camping in the rain, snow or near water bodies. It also dries faster and does not lose all of its insulation properties when wet.

Down materials can be treated with a hydrophobic chemical that lends them a water-resisting coating. Coating the down with this chemical allows it to dry faster and absorb less moisture than untreated down.

However, not all down products in the market today are treated with this chemical yet. So, for us, the synthetic sleeping bag still wins this round.

Cleaning and Maintenance: Synthetic Wins

Cleaning and maintaining synthetic sleeping bags are far more convenient and less hassle. You can simply toss a synthetic sleeping bag in a washing machine and follow the care guidelines stipulated in its manual or tag.

Most synthetic sleeping bags bar the use of harsh cleaning agents and chemicals like bleach and fabric conditioner. They are usually cleaned using only mild detergents. To dry, you can conveniently use a dryer without worrying about damaging its insulation.

On the other hand, a down sleeping bag has a more complex cleaning method. Most down products are not machine washable. The natural oils of the goose down fill are not suited for machine washing as it decreases the loft and insulating power. If accidentally washed in a machine, the down clumps together and may not return to its original shape.

Compressibility: Down Wins

Down sleeping bags easily win the compressibility battle. Of course, seasoned backpackers don’t like to carry more weight than absolutely necessary. Hence, they prefer to carry lightweight essentials, especially if they have to hike long distances or over rugged terrain.

A down sleeping bag can be compressed into a smaller item for easy packability. It also does not weigh a lot. Thus, you don’t have to worry about burdening yourself with a heavy load.

Warmth Insulation: Down Wins

Down has impressive insulating properties that synthetic sleeping bags cannot even match. It works really well during extremely cold weather, especially with winter camping. Sleeping bags with down insulation prevent the draft from getting into your skin by trapping the air as it does with waterfowl.

If you keep a down sleeping bag dry, it is the best companion for the cold. It ensures you stay warm and comfortable enough to get your rest and sleep.

But, it loses its insulating property when wet and takes a long time to dry. If you can keep it dry throughout your trekking adventure, then a down sleeping bag is a definite must-have.

The Verdict

Choosing the right sleeping bag does not only mean choosing the right shape, size, features and accessories. You should also consider the type of insulation it has.

The bag’s insulation determines how much warmth it can provide during cold weather conditions. It gives you comfort from chilly nights while ensuring you can sleep warmly.

Deciding between a down vs synthetic sleeping is crucial for every backpacker and camper. Each of these insulation types has its own advantages and disadvantages.

But, the bottom line is not your preference but what you need at the moment. You should think about the weather conditions and the area where you are going.

Wet and rainy conditions are unsuitable for down sleeping bags, even though they provide superior insulating qualities when dry. Meanwhile, synthetic sleeping bags are budget-friendly and a top choice if you want a more water-resistant and quick-drying sleeping bag. Just be aware that they are heavier and do not pack as small as down bags.


How can I clean my goose down sleeping bag?

The best way to clean a goose down sleeping bag is to wash the exterior by hand. Do not place it directly in a tub of water, as it can damage the fill. To dry the sleeping bag, hang it to air dry.

Can I bring my goose down sleeping bag to a dry cleaner?

For a less tedious process, you can bring it to a dry cleaner and let them do the work for you. But make sure to give them the necessary details on properly cleaning the sleeping bag.

The regular dry cleaning process may still damage the natural oils of the goose down. Dry cleaners should use a special process when cleaning your down sleeping bag.

Is a waterproof stuff sack essential?

You should get a waterproof stuff sack, especially if you have a down sleeping bag. This guarantees the sleeping bag is protected from getting wet, which can hamper its insulating properties.

A waterproof stuff sack may not be necessary for a synthetic sleeping bag. However, it does not hurt to get one because sleeping in a wet synthetic sleeping bag can still be uncomfortable. In addition, a wet bag adds additional weight to your backpack.

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