Mummy vs Rectangular Sleeping Bags – 6 Factors to Consider

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.

Feature	Mummy Bag	Rectangular Bag
Weight	Usually lighter	Usually heavier; summer bags are lighter
Roominess	Not roomy	Very roomy
Warmth	Offers the most warmth	Good warmth, susceptible to cold spots
Versatility	Only useful as a sleeping bag	Can be a quilt, combined with another bag, used as a picnic blanket, and more
Packed Size	Usually smallest	Cold weather bags are bulkier; warm weather bags are very small
Price	Usually more expensive	Usually more affordable

Direct Comparison – Mummy vs Rectangular Sleeping Bags

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 – Direct Comparison

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 – Direct Comparison

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.

Weight – Mummy vs Rectangular Sleeping Bags

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.

• Coleman 0°F Mummy Sleeping Bag
• Coleman Big & Tall Sleeping Bag | 0°F Sleeping Bag

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 rectangular 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.

Roominess – Mummy vs Rectangular Sleeping Bags

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.

Warmth – Mummy vs Rectangular Sleeping Bags

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.

Versatility – Mummy vs Rectangular Sleeping Bags

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.

Packed Size – Mummy vs Rectangular Sleeping Bags

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 rectangular sleeping bags 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.

Price – Mummy vs Rectangular Sleeping Bags

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 Other Types of Sleeping Bags? – Mummy vs Rectangular Sleeping Bags

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 Characteristics of Sleeping Bags Are Best? – Mummy vs Rectangular Sleeping Bags

The most important characteristics of sleeping bags are insulation, weight, warmth, size and shape.

1. Insulation: The insulation of a sleeping bag is the material that is used to keep you warm while you sleep. The two main types of insulation are down and synthetic materials. Down is lightweight and compressible, making it ideal for backpacking trips where space is limited. Synthetic materials are more affordable and perform better in wet conditions.
2. Weight: Sleeping bags can vary greatly in weight depending on the type of insulation used and the overall design. For backpackers, a lightweight sleeping bag is crucial as it reduces the amount of weight they have to carry during their trip.
3. Warmth: A sleeping bag’s warmth rating indicates the temperature at which it will keep you comfortable while sleeping. It’s important to choose a sleeping bag with an appropriate warmth rating for your intended use to avoid being too cold or too hot during the night.
4. Size: Sleeping bags come in different sizes to accommodate different body shapes and sizes. It’s important to choose a sleeping bag that fits your body properly to maximize warmth retention.
5. Shape: Sleeping bags come in different shapes, such as mummy or rectangular or semi-rectangular. Mummy-shaped bags offer maximum warmth retention due to their close fit around the body, which may feel restrictive for some people, while rectangular bags provide more room to move around but may be less warm due to their looser fit.

All these characteristics are important because they directly affect how comfortable you will be while using your sleeping bag outdoors, particularly during camping trips or hiking expeditions where good quality sleep is essential for physical performance the next day. Choosing a well-insulated, appropriately sized and shaped sleeping bag with an appropriate warmth rating can make all the difference between having an enjoyable outdoor experience or enduring a miserable one due to being either too cold or too hot during the night.

Do I Need a Sleeping Pad? – Mummy vs Rectangular Sleeping Bags

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.

Conclusion: The Verdict – Mummy vs Rectangular Sleeping Bags

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 versatile. Consider these points when you’re making your selection so you can select the best sleeping bag for you.

Frequently Asked Questions – Mummy vs Rectangular Sleeping Bags

What is the Difference Between a Mummy Sleeping Bag and a Rectangular Sleeping Bag? – FAQs

The primary difference between a mummy and a rectangular sleeping bag is their shape. Mummy bags are narrower at the feet and wider at the shoulders to mimic the shape of a mummy’s body. They fit snugly around the body, with less space inside to maximize heat retention. Rectangular sleeping bags, on the other hand, are more spacious and provide more room for movement, which can be beneficial for those who feel claustrophobic in small spaces.

Mummy sleeping bags are generally thought to be warmer than rectangular bags due to their close-fitting design, which reduces air pockets within the bag. This means they are better suited for colder weather and higher altitudes where staying warm is critical. They are also lighter in weight than rectangular sleeping bags because their tapered shape requires less insulation material.

Rectangular sleeping bags, on the other hand, allow for more movement inside, making them more comfortable for people who find mummy bags too confining. They are also less expensive than mummy bags because less specialized materials and construction techniques are required. Rectangular sleeping bags can also be zipped together with another bag of a similar size and style to make a double sleeping bag if necessary.

In conclusion, while both types of sleeping bags serve the same function – keeping you warm while sleeping outside – they differ significantly in terms of design and intended use. The decision between a mummy sleeping bag and a rectangular sleeping bag comes down to personal preferences, comfort level, and intended use case scenarios such as weather conditions, outdoor activities, or camping locations, among others.

Are There Any Activities that Lend Themselves Better to One Type of Sleeping Bag Over the Other? – FAQs

Yes, there are some activities that require a different type of sleeping bag than others.

Mummy sleeping bags are ideal for activities requiring a high level of warmth retention, such as mountaineering or winter camping. They are designed to be lightweight and packable, making them easy to carry on long hikes or climbs. Mummy bags are also more weather resistant than rectangular sleeping bags, making them a good choice in cold and wet weather.

Rectangular sleeping bags, on the other hand, are better suited for activities where comfort takes precedence over warmth retention. They provide more interior space and can be more comfortable for people who feel claustrophobic in small spaces. Rectangular bags are also ideal for car camping trips where weight and packability are less important factors.

Furthermore, rectangular sleeping bags can be zipped together with another bag of a similar size and style to form a double sleeping bag, which is useful for couples or families who want to share a bed while camping.

Overall, the decision between a mummy and a rectangular sleeping bag is influenced by the activity at hand as well as your personal preferences. When choosing a sleeping bag for any outdoor activity, consider weather conditions, expected temperatures, weight requirements, packability requirements, and personal comfort level.

How Do I Decide Between a Mummy Sleeping Bag and a Rectangular Sleeping Bag? – FAQs

The decision between a mummy and a rectangular sleeping bag can be influenced by a number of factors, including your intended use, personal preferences, and budget. 

Here are some things to think about before making your decision:

• Intended Use: Consider the activities you intend to do with the sleeping bag. A mummy sleeping bag may be more suitable for camping in colder weather or at higher altitudes due to its snug fit that maximizes warmth retention. A rectangular sleeping bag may be more comfortable if you plan on car camping or backpacking in warmer weather.
• Temperature Rating: Look for sleeping bags that have temperature ratings that correspond to the conditions you’ll be experiencing. Mummy bags have lower temperature ratings than rectangular bags because of their close-fitting design, which reduces air pockets within the bag.
• Size and Weight: Think about how much space you have available for carrying your gear and how much weight you’re willing to carry. Mummy bags are lighter and smaller than rectangular bags, making them easier to transport on long hikes or climbs.
• Sleeping Position: Consider whether you move around a lot while sleeping or prefer to sleep in one position all night. If you toss and turn at night, a rectangular sleeping bag may give you more room to move.
• Price: Determine how much you’re willing to pay for a sleeping bag. Due to the specialized materials and construction techniques used in mummy bags, they are more expensive than rectangular bags.

Ultimately, the decision between a mummy sleeping bag and a rectangular sleeping bag comes down to personal preference and intended use case scenarios such as weather conditions, outdoor activities, or camping locations, among others. It is critical to try on various types of sleeping bags before making a purchase in order to find one that is comfortable, fits well, meets your needs, and provides good value for money.