Mummy vs Rectangular Sleeping Bags – 6 factors to Consider

By Emma
mummy vs rectangular sleeping bag

It may be unexpected, but there’s more than one type of sleeping bag, and different ones work best for different situations.

Mummy sleeping bags are best for cold weather camping, as you can tuck yourself up nicely in the bag. Rectangular sleeping bags are great for warmer weather and also perfect if you’d like a roomy sleeping bag.

I have some experience with both, and I’ve also done some research to back up my own experiences. Let’s dive in.

FeatureMummy BagRectangular Bag
WeightUsually lighterUsually heavier; summer bags are lighter
RoominessNot roomyVery roomy
WarmthOffers the most warmthGood warmth, susceptible to cold spots
VersatilityOnly useful as a sleeping bagCan be a quilt, combined with another bag, used as a picnic blanket, and more
Packed SizeUsually smallestCold weather bags are bulkier; warm weather bags are very small
PriceUsually more expensiveUsually more affordable

Mummy vs Rectangular Sleeping Bag Direct Comparison

There are some key differences between mummy and rectangular sleeping bags.

Comparing these bags will help you determine which one is best for you, and I’ll dive deeper into their attributes in a few moments.

Mummy Sleeping Bag

Mummy sleeping bags are shaped a little like a sarcophagus, and they conform to the shape of your body. 

They have tapered ends and a hood. This is so there’s almost no ambient space for cold air to circulate in them, and they keep you snug in cold weather.

They’re generally compact due to their shape, and this makes them fantastic for backpackers. However, if you’re claustrophobic, then you may not like this.

Rectangular Sleeping Bag

Rectangular sleeping bags are shaped like a mattress, so they’re bulkier due to the additional fabric, but they provide more room for movement. If you toss and turn a lot, then a rectangular sleeping bag is probably the best choice.

Rectangular sleeping bags are better for car camping as they weigh more, so they’ll be more of a chore to carry while backpacking or walking to a campsite.

Although they’re best for warm weather camping, rectangular sleeping bags can add plenty of insulation and heat when it’s colder. However, you’re more likely to have cold spots in them, so keep that in mind.

If you’re unsure of what I mean by insulation, you can read about how it works here. Insulation is most commonly discussed related to your house, but the premise applies to sleeping bags, too.

Mummy vs Rectangular Sleeping Bag Weight

Winner: Mummy bag

Weight matters most if you’re backpacking or if you have to walk a long way to get to your site. When car camping, weight is always going to be less of an issue.

If lightweight is what you need, then a mummy sleeping bag is best for you.

Let’s take two bags from the same brand to compare their weight.

I selected two from the same brand so it’s fair, and you can already see that the mummy bag weighs less. It weighs five pounds, and the rectanglular bag weighs almost 6 pounds.

There are some other rectangular sleeping bags that weigh almost 13 pounds that are also from Coleman, but it’s rare you’ll find a mummy bag that weighs that much.

Mummy vs Rectangular Sleeping Bag Roominess

Winner: Rectangular bag

Ultimately, if you’re choosing a sleeping bag based on roominess, then you’re going to want to base it on preference.

Mummy sleeping bags are narrower around the head and wider at the shoulders, then they taper as they get towards the feet. You can’t really open and close your legs, bend your knees, or toss and turn in them unless you want the entire bag to move with you.

Rectangular sleeping bags leave your room to open and close your legs, cross them, bend your knees, and wriggle all around without the bag moving with your body. 

Consider your usual sleeping positions before choosing to help you determine which is best for you.

Mummy vs Rectangular Sleeping Bag Warmth

Winner: Mummy bag

Mummy bags are always going to be best for warmth. They have hoods and they fit tightly to your body, so there’s almost no room for cold air to get at you, and they’re compact enough to avoid cold spots forming. 

It’s very rare that you’ll find a mummy bag made only for warm-weather camping; they’re usually cold-weather specific or 3–4 season bags. On the other hand, rectangular bags are usually sold as all-weather or warm weather bags. 

There are a few that are sold for cold weather; for example, the Coleman sleeping bag I recommended earlier. Both the rectangular and mummy bags have a temperature rating of 10 degrees Fahrenheit.

However, just because two bags have the same temperature rating, doesn’t mean you’ll be equally warm in each.

You can make rectangular bags warmer by wrapping the ends around your feet and putting hot water bottles throughout the bag, but mummy bags will always be warmer.

In fact, I highly recommend mummy bags for cold weather camping, and you can check out these cold weather camping tips for more of my suggestions on staying warm.

Mummy vs Rectangular Sleeping Bag Versatility

Winner: Rectangular bag

Mummy sleeping bags aren’t that versatile. They can only be used as a sleeping bag, and they only fit one person. 

However, rectangular sleeping bags are great for fitting two kids in, or you can completely unzip them and use them as a quilt for two people. They can also sometimes be attached to other bags to be made into double bags.

You can even use rectangular sleeping bags as picnic blankets if you wish.

Overall, rectangular bags win in terms of versatility.

Mummy vs Rectangular Sleeping Bag Packed Size

Winner: Rectangular bag

Let’s compare the products discussed earlier in terms of pack size.

The mummy sleeping bag rolls up to 17.1 x 12.35 x 12 inches. The rectangular sleeping bag rolls up to 20 x 11 x 11 inches. It’s a subtle difference, yes, but even minor differences matter if you’re trying to fit your sleeping bag into a backpack.

Sometimes rectangular sleeping bags are smaller, though. Packed sizes are often material-based. Mummy bags with thick material will be bulkier than a rectangular sleeping bag made for warm weather. 

The Coleman Sun Ridge 40°F Warm Weather Sleeping Bag rolls up to 8.5 x 16.3 x 10.39 inches. That’s to be expected, as it’s very light.

Generally, though, if the two bags have similar purposes, then the mummy bag will be smaller.

Mummy vs Rectangular Sleeping Bag Price

Winner: Rectangular bag

If you look at two sleeping bags from the same company, then you can generally expect the same quality in the bag. However, price doesn’t always indicate quality.

High-quality bags have thick materials, at least a 10-degree temperature rating, and they’re made of polyester or nylon with lots of insulation. Synthetic bags and down bags have a similar quality, and synthetic bags should cost less.

If you come across an expensive bag that doesn’t disclose its material and refuses to give a temperature rating, then it may not be the highest quality bag, and you should look elsewhere. A lower-priced bag may be far better quality than a questionable bag with a higher price.

Once you settle on a high-quality, trustworthy brand for your bag, then price differences between different types of bags often aren’t huge.

With the two Coleman bags mentioned earlier, the mummy bag is less than $20 lower in price than the rectangular bag. This is likely because it has less material used in its construction.

However, mummy bags are often more expensive than rectangular sleeping bags. When doing a search for mummy bags, the prices are generally higher across all brands. 

The lowest-priced mummy bag I found on the first page of the search doesn’t dip below $30. The lowest-priced rectangular bag is barely over $20.

Mummy bags are likely more expensive because of their shape. They have a tailored fit that takes more effort to design and produce. But again, it can go the other way, and they can be cheaper due to less material used.

It’s always going to depend on the brand and the bags in question, but mummy bags are usually just a little more expensive than rectangular bags.

Is There Another Type of Sleeping Bag?

There are a few other types of sleeping bags, although mummy and rectangular sleeping bags are the most common. Let’s look at the other types of sleeping bags that you may encounter:

  • Hybrid: They’re slightly tapered into more of an oval shape, and they’re a middle ground between mummy and rectangular sleeping bags.
  • Sleeping pods: Sleeping pods are roomier sleeping bags. They don’t provide as much heat as sleeping bags, so they’re great for summer camping if you want something roomy to sleep in.
  • Bivys: Bivys are like a cross between a tent and a sleeping bag. They’re roomier than a sleeping pod, and they have more structure than them. The extra room in them is usually a dome-like structure above the torso, but the rest of the bivy fits close to your body. It’s best to use another sleeping bag inside the bivy.

Which Type of Sleeping Bag is Best? 

A lightweight but highly insulated sleeping bag is best for most occasions. It keeps you safe from the cold and will be easy to carry in various situations. This is usually a mummy sleeping bag.

Do I Need a Sleeping Pad?

Using a sleeping pad gives you more warmth and comfort than using a sleeping bag on its own. It’s more beneficial to sleep with one than without one.

If you want to read more about whether or not you should use a sleeping pad, read about “Do You Need a Sleeping Pad” here.

The Verdict

There’s no winner when we’re looking at mummy vs rectangular sleeping bags. Each type wins in different categories, and in the end, the best bag for you depends on your situation and preferences.

Mummy bags are best for cold weather and backpacking, and rectangular bags are best for being more affordable, roomier, and more versatile. Consider these points when you’re making your selection so you can select the best sleeping bag for you.

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My name is Emma, and I’m a city dweller who jumps on every opportunity to get out and enjoy nature! I’ve gone on a number of car camping and backpacking trips over the past few years. I created this site to inspire others to get outside and to make the process easier for you.