When choosing a down sleeping bag, it is easy to assume goose down is automatically warmer, lighter or simply better than duck down, but it isn't that simple.

While goose down can reach exceptionally high fill power ratings, the type of bird is only a small part of the picture. When comparing sleeping bags for hiking, bushwalking, hunting or camping in Australia, factors like the EN/ISO temperature rating, fill power, fill weight, sleeping bag construction and moisture resistance are far more useful.

So, if you are comparing goose and duck down sleeping bags, don't stop at the label. Here's what actually matters.

Is Goose Down Better Than Duck Down?

Not necessarily.

Both goose down and duck down insulate in essentially the same way. The fine down clusters create loft, trapping small pockets of air that slow heat loss from your body.

Goose down does have an advantage at the very top end of the market because geese generally produce larger down clusters. This allows premium goose down to reach extremely high fill power ratings, including 850, 900 and even 1000+ fill power.

High-quality duck down can also achieve impressive loft, with premium examples reaching around 800 fill power.

For most sleeping bags, however, comparing the bird species tells you much less than comparing the actual specifications of the bags.

Duck Down vs Goose Down at the Same Fill Power

This is where much of the confusion disappears.

Duck down and goose down with the same fill power offer broadly comparable insulating efficiency.

A 700 fill power duck down and a 700 fill power goose down both loft to a similar volume for a given weight of down.

Where goose down has an advantage is its ability to reach higher fill powers. That becomes valuable when manufacturers are trying to produce an exceptionally light and compact sleeping bag for alpine expeditions or ultralight travel.

For more typical three-season and four-season sleeping bags, quality duck down can deliver excellent warmth-to-weight performance at a more accessible price than goose down.

What Does Fill Power Mean?

Fill power, sometimes called loft, is a standardised measure of how much volume a set weight of down occupies when fully lofted.

The higher the number, the greater the loft and the more efficiently the down can trap insulating air.

As a general guide:

• 200 to 500 fill power: lightweight insulation for warmer conditions and summer use
• 550 to 650 fill power: good general-purpose down insulation
• 650 to 750 fill power: excellent for hiking, hunting and backpacking
• 800+ fill power: high-efficiency insulation for ultralight and alpine sleeping bags

Higher fill power can help a manufacturer achieve a particular temperature rating using less insulation, resulting in a sleeping bag that can be lighter and more compressible.

But fill power should never be viewed on its own.

A sleeping bag containing a small amount of 800 fill power down may be less warm than one containing considerably more 650 fill power down. Baffle construction, bag shape and insulation distribution also influence the final performance.

That is why temperature testing matters.

Why Goose Down Has a Premium Reputation

There is some truth behind goose down's reputation.

Geese are generally larger birds and can develop larger down clusters than ducks. Those larger clusters can produce exceptional loft, which is why goose down dominates at the extreme end of the fill power scale.

Premium goose down can therefore offer an outstanding warmth-to-weight ratio when every gram and every centimetre of pack space counts.

Goose down clusters can also be slightly more resilient over very long periods of use.

But those advantages do not mean a sleeping bag labelled "goose down" is automatically better than one filled with duck down.

A well-designed, EN/ISO-rated duck down sleeping bag may be a much more appropriate choice than a lower-performing goose down alternative.

Goose Down vs Duck Down: The Key Differences

For most hikers, bushwalkers and campers, the difference between two complete sleeping bags will be determined far more by their temperature ratings, construction and total insulation than by whether the down came from a goose or duck.

What Should You Look for in a Down Sleeping Bag?

If you are choosing a sleeping bag for Australian conditions, there are four specifications worth paying much closer attention to.

1. Check the EN/ISO Sleeping Bag Temperature Rating

This should be one of your first comparisons.

Standardised sleeping bag testing makes it possible to compare the thermal performance of different bags and brands under controlled conditions. Domex sleeping bags are tested according to EN ISO 23537-1:2022.

You will commonly see three figures:

Comfort: The temperature at which a standard cold sleeper is expected to sleep comfortably.

Limit: The temperature at which a standard warm sleeper can sleep comfortably.

Extreme: A survival-oriented rating rather than a comfortable sleeping temperature. It should never be used as your target temperature when choosing a sleeping bag.

For example, the Domex Venture has EN ratings of approximately -3.3°C Comfort, -9.8°C Limit and -28.8°C Extreme.

For most people, the Comfort and Limit figures provide far more useful information than the words "duck" or "goose" on the insulation specification.

It is also important to remember that EN testing is carried out using an insulated sleeping mat. If your mat has a lower R-value, your sleeping bag may not perform as expected.

2. Don't Forget Your Sleeping Mat

Your sleeping bag is only half of the sleep system.

The fill beneath your body becomes compressed when you lie on it. Once compressed, it cannot trap nearly as much insulating air.

That means your sleeping mat provides much of the insulation between you and the cold ground.

For cooler conditions, pairing your sleeping bag with a suitably insulated mat is essential. An R-value of around 4 or higher is a useful starting point, with higher R-values required as ground temperatures drop.

This is particularly important for winter camping, high-country trips and alpine conditions, where ground temperatures can make a significant difference to how warm your sleep system feels.

A highly rated sleeping bag sitting on an inadequately insulated mat may therefore feel considerably colder than expected.

When planning a sleep system, think about the sleeping bag and sleeping mat together, rather than treating them as separate pieces of equipment.

3. Compare Fill Power

Once you know a sleeping bag is warm enough for the conditions you expect, fill power becomes particularly useful.

Higher fill power means the down can create more loft for its weight.

For hikers and bushwalkers carrying everything on their backs, that can translate into two valuable advantages: less weight and less packed bulk for a given level of insulation.

Around 500+ fill power provides an excellent balance for general backpacking and bushwalking, while 800+ fill power is more commonly associated with ultralight or alpine equipment.

Again, remember that higher fill power does not automatically mean a warmer finished sleeping bag. Use the EN/ISO rating to compare warmth.

4. Consider Hydrophobic Down

Traditional down performs brilliantly while dry but loses much of its loft when saturated.

And while Australia is often associated with dry conditions, moisture can still be a real consideration when camping. Condensation, wet weather, damp gear, coastal humidity and rapidly changing alpine conditions can all expose a sleeping bag to moisture during a trip.

Hydrophobic down is treated to resist moisture absorption and retain loft more effectively in damp conditions.

It is not waterproof, and a down sleeping bag still needs to be protected from heavy rain and saturation, but the treatment provides an additional margin of protection when conditions turn damp.

The Domex Versalite, Venture and Zenith use 650 loft hydrophobic duck down, combining excellent warmth-to-weight performance with greater resistance to moisture.

The Versalite, for example, weighs just 850 g in the Standard size while achieving EN ratings of 0°C Comfort and -5.9°C Limit.

The Venture steps up to -3.3°C Comfort and -9.8°C Limit, while the Zenith is designed for considerably colder conditions.

What About Untreated Down Sleeping Bags?

Hydrophobic down is not essential for every trip.

Domex sleeping bags, including the Wanderer and Trailblazer, use traditional RDS-certified duck down and offer an affordable option for people who do not necessarily need the additional moisture resistance of hydrophobic insulation.

These bags can also be treated using a specialist down-proofing treatment such as Nikwax Down Proof to improve water repellency.

The Trailblazer 500, for example, combines 500 g of RDS-certified duck down with EN ratings of approximately 0.1°C Comfort and -5.8°C Limit, making it a capable three-season option.

So, Is Goose Down Worth Paying More For?

If your objective is an extremely light alpine sleeping bag and you are chasing the highest possible warmth-to-weight ratio, premium 850 to 1000 fill power goose down can be exceptional.

For most Australian hiking, bushwalking, hunting and camping, however, a much better question is:

"Which sleeping bag gives me the right temperature rating, weight, packed size and moisture protection for where I'm going?"

A quality duck down sleeping bag with the right EN/ISO rating can outperform a poorly specified goose down bag for the trip you actually intend to take.

Choosing the Right Down Sleeping Bag for Australia

When comparing sleeping bags, look beyond the species printed on the tag.

Prioritise:

1. EN/ISO temperature rating appropriate for the conditions
2. A suitable sleeping mat and R-value, ideally at least R4 for cooler conditions
3. Fill power and overall weight if packability matters
4. Hydrophobic treatment for additional protection in damp environments
5. Bag construction and fit, including hood, draught collar and baffle design

Goose down can achieve extraordinary levels of loft, but duck down is far from the second-best alternative it is sometimes portrayed as.

Choose the specifications that suit the trip, rather than choosing the bird.