Guide to Lightweight Sleeping Bags for Hiking

As a general rule, sleeping bags designed for hiking and trekking are also suitable for camping. But the reverse of this is almost never the case, unfortunately.

There are 2 reasons why – packed size and weight.

A sleeping bag needs to fit inside a rucksack, along with all your other gear, and contribute as little as possible to the weight you will be lugging along the trail.

The Black Wolf 3D 500 Bag is still going to be too bulky and heavy to fit in a rucksack when compressed.

Small & light is better for hiking

In the above picture, we have a 70L rucksack, which is a good sized pack for most hiking and trekking adventures.

The Black Wolf 3D 500 sleeping bag in the image above is a popular style for general camping. It has a synthetic fill and a comfort temperature rating of approximately -5 °C. As you can see it’s going to occupy a significant amount of real estate in your pack.

Even when compressed, as can be seen on the right of the image, it is still a big unit, and what’s even worse is that it weighs in at about 3 kg. This sleeping bag is best kept for car camping trips.

The Latitude LtI Sleeping bag is half the size and weight when compressed compared to the 3D 500 above.

In the above image, we have the same 70L rucksack and a Sea to Summit Latitude LtI which a good all-rounder down-filled sleeping bag. It shares a similar comfort rating as the sleeping bag mentioned above (approx. -4 °C). Even before it is compressed it is far smaller than the camping sleeping bag featured in the top image.

Furthermore, on the right you can see the same bag compressed ready to be stashed in a rucksack. Not only is it less than half the size, at 0.88 kg, it is less than half the weight of the sleeping bag mentioned above.

This is the sort of packed size and weight you should be aiming for in a hiking and trekking sleeping bag.

What’s the difference in design?

Sleeping bags that are designed for camping are usually square in shape, roomy, comfortable and made with tough, durable fabrics. Packed size and weight are generally a secondary consideration in their design.

A hiking bag is usually tapered, often mummy in shape for thermal efficiency (more on this later), are made with lighter fabrics and have a hollow fibre synthetic or down fill material. They are designed primarily to offer warmth at a minimal weight and packed size.

There are some bags that straddle the gaps between weight, packed size and internal space. The Trek Sleeping Bags from Sea to Summit are a good example of this.

The Trek TkIII Sleeping bag is an example that balances space and weight well. Image: Sea to Summit

What is all the sleeping bag terminology?

Firstly, let’s talk about shapes, which there are quite a few of. Each sleeping bag shape is often also available in different sizes/lengths to suit every individual.

The most common shapes are:

1. Square

This offers lots of internal space and can be either with or without a hood. This shape is usually found on general use camping sleeping bags that are made for comfort.

2. Tapered

A tapered cut reduces some of the dead space in a sleeping bag which improves thermal efficiency. These are a good shape for those wanting space in their sleeping bag whilst trying to save on weight.

3. Mummy

Mummy shapes have a figure-hugging cut, there’s little to no dead space in the bag, so they can trap a layer of warm air right next to your body. These are designed purely for efficiency and are preferred by alpinists wanting the best warmth to weight ratio from their sleeping bag.

This hoodless and tapered design is great for warm weather or hostel use. Image: Sea to Summit

Some of the less common shapes are: 

1. Hoodless tapered

Hoodless tapered bags are a good choice for travel when you want a compact sleep solution to use in hostels. These are also popular lightweight bags for summer adventures.

2. Quilt

Generally kept for warm weather adventures, the concept of a quilt is that it will provide warmth over the top whilst your mat provides warmth from underneath. They are usually found in the rucksack of an ultra-lightweight hiker as the absence of zips or a hood shaves off extra grams for those who are conscious of how much weight they’re carrying.

3. Women’s specific

A women’s specific bag is usually roomier in the hip area and will be generally shorter in length to prevent any dead space. Women’s model bags will also often have extra insulation in areas, such as the footbox and the torso.

Women may find that female-specific bags provide a tailored sleeping experience for technical expeditions. Image: Sea to Summit

Now for the terminology:

Baffles

Simply described, these are the cavities between the stitching on a sleeping bag. This term is often used when referring to a down bag where the baffles stop all the down from ending up at one end of the bag.

Footbox

Most general-use sleeping bags taper to a point at the end, which, if you are tall, doesn’t leave a lot of room for your feet. A footbox is usually found on tapered and mummy shaped bags where a three-dimensional box creates space for your feet to rest without feeling restricted or pushing against the side of the bag.

Baffles section off the fill of a bag so that you have even insulation and warmth. Image: Thermarest

Draft tubes

These insulation filled tubes run alongside the zipper on the inside of the bag. They are designed to fill the insulation gap created by the zipper and minimise airflow through the zipper.

Neck/chest baffle

This is situated inside the sleeping bag around the top of your shoulders. It can usually be tightened to keep the warm air from escaping out the top.

Hood

This is the bit that goes over or sits under your head. These too can be either flat or three dimensional in their design. You lose about 30% of your body heat from your head, so having a good hood that efficiently hugs your head is going to make a big difference on a cold night.

A 3D hood will add extra warmth when the conditions are chilly. Image: Sea to Summit

Should I get a down or a synthetic sleeping bag?

The fill is what gives a sleeping bag its thermal properties, and there are two types of material used – down and synthetic.

Both of these materials have pros and cons, but both are suitable for hiking and camping. Without getting too technical, I’ll summarise both for you below.

Down

• You’ll find both duck and/or goose down in a sleeping bag.
• Duck down is more cost efficient, but goose down offers better performance.
• Down is differentiated by a loft rating (650, 700, 850+). The higher the rating, the more warmth you get at a lesser weight.
• Down bags pack up much smaller and offer excellent warmth to weight ratio.
• If looked after, down bags can last for decades.
• If down becomes wet it loses all its warmth-retaining properties.
• Down bags are expensive when compared to synthetic bags.

Down bags are generally warmer but come at a cost. Image: Sea to Summit

Synthetic

• There are hundreds of proprietary synthetic fibres on the market. Some of these include Thermolite, Primaloft, or Hyperloft.
• Synthetic fill does not compress as much and does not provide the same warmth to weight ratio as down.
• Hollow fibre synthetic offers the best performance for a synthetic fill.
• Synthetic bags offer some insulation even if wet and are easy to care for.
• If synthetic fill starts to break down, the sleeping bag cannot be rejuvenated.
• Synthetic filled bags are more affordable than down.

Synthetic bags can be a little easier to maintain. Image: Sea to Summit

Choosing the right temperature rating

There’s no clear-cut answer here, so the best advice we could give is to make sure you choose a bag with a comfort rating (not extreme rating) that is 5 to 10 degrees lower than the average temperature you expect to be spending most of your time sleeping in.

Remember, a sleeping bag can be warmed up a little with extra clothing and a thermal liner and it can also be unzipped and used as a duvet on warm nights, so sticking to an average expected temperature will give you the most versatility. Check out this article here to help you better understand sleeping bag temperature ratings.

How much does a sleeping bag for hiking cost?

As you’ve probably guessed, there’s no straightforward answer here. For a reliable synthetic filled bag for hiking, prices start at around $120 AUD and extend to above $300 AUD, depending on the make.

For a good quality all-round-use down sleeping bag, you can expect to pay $300-400 AUD, whereas a technical or specialist sleeping bag can set you back $700+ AUD.

Pick a temperature rating that reflects the conditions you’ll be using the bag most in. Image: Sea to Summit

Can I just stuff my sleeping bag back into its storage sack?

Yes, in fact, this is what we recommend. Even though the process of ramming your sleeping bag into its storage sack seems somewhat careless compared to neatly folding and rolling it, it can actually be better for the bag.

This is especially relevant for synthetic filled bags, let me explain why.

When rolling the bag, you often need to fold it in half first, and this fold often ends up being in the same spot every time, which with repetition can cause the fibres to break or separate along the fold and create a cold spot.

The process of tightly rolling a sleeping bag also places tension on the synthetic fibres around the outside of the roll, potentially causing them to break. It also tends to encourage the fill to remain in a flat rather than lofted state.

Stuffing your synthetic sleeping bag overcomes both of these issues. It may look all crinkled next time you pull it out, but it’s going to keep you a whole lot warmer.

As for down bags, stuffing is just far easier than rolling, you just need to be gentle. And if your bag has a waterproof shell, turn it inside out before stuffing so the air escapes from the bag easily during the process.

Check out the video below where we show you how to do this for both general camping and lightweight hiking sleeping bags.

In this video, we show you the best way to pack up a down bag and a synthetic bag.

Storage & care

No matter which type of sleeping bag you have, proper care will ensure you get the longest life out of your investment. Only wash your bag when absolutely necessary, as repetitive washing can contribute to the fill material breaking down.

The use of a liner extends the life of your sleeping bag as you can wash the liner regularly rather than the sleeping bag.

Synthetic bags are easy to care for as they can be placed in a front loading washing machine with normal detergent on a gentle cycle and hung out to dry.

Down sleeping bags require a little more care and consideration, check out this article for a full guide on washing, storing and caring for your down sleeping bag.

That’s all the advice we have for choosing a sleeping bag for your lightweight adventures – whether it be for kayaking, climbing, bike touring or trekking. Whichever sleeping bag you land on, we hope you sleep soundly in it on your next adventure.

 

Do you prefer down or synthetic bags for hiking?