Choosing a sleeping bag feels weirdly technical when all you want to do is nap outside, but having the right bag really can make or break a camping trip. Here are my tips and tricks for picking the best sleeping bag so that you can enjoy a good night’s sleep under the stars.
Before you start…
You should pick a sleeping bag based on the conditions you’ll be camping in. The features you need are going to depend on:
- Where you are camping
- Where you are sleeping (tent, car, etc.)
- What time of year it is
- How cold it gets at night
How do sleeping bag temperature ratings work?
Choosing the right sleeping bag really comes down to choosing the right temperature rating.
To ensure consistency across companies, sleeping bag manufacturers usually send their bags to a third party for testing. If you see EN or ISO on your sleeping bag, then you know that your bag was tested by independent lab and that you can feel pretty confident when comparing across brands.
Message from the Field Lab: EN (European Norm) was the older standard, ISO (International Standards Organization) sets the standards now. Both are similar, so you can compare an older EN bag with a newer ISO bag straight across (without having to do any mental somersaults).
Comfort vs. limit vs. extreme sleeping bag ratings
- Comfort rating: the air temperature that a cold sleeper *could* be comfortable at
- Limit rating: the air temperature that a hot sleeper *could* be comfortable at
- Extreme rating: in an emergency situation, the air temperature where the bag will barely be able to keep you alive before you die from hypothermia (fun)
FYI — Just because you *could* be comfortable at this temperature doesn’t mean you will be.
(Unless you know that you run hot) it’s usually better to go by comfort rating and be too hot, than go by limit rating and be too cold. You can always unzip your sleeping bag for some fresh air.
Comfort rating = thriving. Limit rating = surviving. Extreme rating = survival.
It’s always sleeping bag season!
Sleeping bags are plunked into three categories based on their temperature ratings:
- Summer: bags with a temperature rating of 0C or higher
- 3-season: bags with a temperature rating somewhere between -15C to -1C
- 3-season = spring, summer, fall
- Winter: bags with a temperature rating -16C or lower
* If someone says “1-season sleeping bag” they mean summer (even though I guess that technically winter sleeping bags are for one season too).
Pro-tip: If you are camping in Alberta, I’d opt for a 3-season bag regardless of the season, because the nights get chilly here in the summer too. That is unless you are camping in the winter, in which case you will 100% want a winter sleeping bag.
Why do women’s bags and unisex bags sometimes differ in their temperature ratings?
Women’s bags are often labelled using the comfort rating, while unisex bags tend to use the limit rating. They do this because the average female has a lower body temperature than the average male. But in this case, “average” literally means nothing — pick a sleeping bag off of how YOU sleep at night.
Pro-tip: Sometimes the manufacturer will incorporate the rating into the bag’s name — this is no substitution for reading the actual label! First off, you want to know which of the ratings they are referencing in the name. Reading the label is also important because even though the industry has tried to standardize things, they are allowed to round up or round down (to the nearest 5 degrees) when including the number in the name. So while you think your Sleeping Bag Ultra 5 will be good for 5C, it could actually be more of a Sleeping Bag Ultra 9. Four degrees is a big difference when it comes to sleeping comfortably!
Picking the right type of sleeping bag insulation
Sleeping bags usually come stuffed with one of two kinds of insulation: down insulation or synthetic insulation.
Down Insulation
Down comes from ducks and geese — it is the soft fluffies close to the body, under the feathers.
- Down insulation is going to be warmer than synthetic insulation.
- It is easier to pack around because it is lighter and compresses better.
- It tends to be more durable.
But…
- Down insulation loses loft when it gets wet and so it won’t do as good of a job at keeping you warm when it’s wet.
- It tends to be more durable when it is cared for properly — down requires special care.
Down also comes with ethical implications. “Ethical down” means it was sourced from animals that were raised for meat, as opposed to down from live-plucking. Something to consider when you pick your sleeping bag.
Synthetic Insulation
Synthetic insulation is made of polyester and looks like big clumps of cotton candy.
- Synthetic insulation is often much cheaper than down.
- It is still going to keep you insulated if it gets wet.
But…
- It’s bulkier and heavier than down.
- Synthetic insulation isn’t as durable and loses it’s loft faster over time.
Can you just use a blanket instead?
Absolutely! Sleeping bags are designed to keep you warmer and to pack down better, but that doesn’t mean you can’t get by with a blanket. However, if the nighttime temperatures are dropping below 10C, you’ll probably definitely want a sleeping bag. And even above 10C, you might be just getting by with a blanket.
What sleeping bag insulation should you choose?
You might want to consider down insulation if you are camping in cooler temperatures or if you are taking the sleeping bag with you on hiking trips. Otherwise, most people get along just fine with synthetic insulation (and often prefer it because of its performance when wet).
Cozy geometry: sleeping bag shapes
Sleeping bags typically come in one of three shapes — rectangular, semi-rectangular, and mummy bags. The shape determines how much space you have, and space comes at the cost of warmth.
Rectangular bags sacrifice warmth for more wiggle room. Mummy bags are the warmest but come with an I-am-a-human-sardine feeling.
- Rectangular: maximum space, minimum warmth
- Semi-rectangular (barrel): moderate space, moderate warmth
- Mummy: minimum space, maximum warmth
For couples wanting to sleep together, you can get compatible rectangular sleeping bags (one has a right zipper, one has a left) and zip them together to make one big sleeping bag. You can also buy a double bag, but buying the two sleeping bags separately gives you the option to use them together or apart.
What sleeping bag shape should you pick?
Depends on your needs — a rectangular bag is going to be fine for car camping, but you might want something a bit more fitted (i.e., warmer and lighter) if you are going into the backcountry.
Finding the right sized bag
Sleeping bags can come in different lengths and widths to accommodate different body sizes and sleeping positions.
We know that more space = less warmth (and vice versa), so if you are worried about warmth then you’ll want to pick a sleeping bag that makes sense for your height and minimizes unnecessary length.
Pro-tip: Manufacturers will often include a maximum height for each sleeping bag. Pick the smallest fit without exceeding the maximum height.
Pro-tip: If you are a restless sleeper, opt for a wider sleeping bag to give you extra space to flail.
What’s the difference in sizing between unisex sleeping bags and women’s sleeping bags?
A women’s sleeping bag is usually shorter, narrower at the shoulders, and wider at the hips.
Sleeping bag fabrics — what the shell?
When you think of sleeping bag fabric, you probably think of the shiny outer shell, but the lining is just as important!
The sleeping bag’s outer shell
Sleeping bag shells are usually made of rip-stop nylon or polyester.
- Rip-stop nylon: durable and lightweight
- Polyester: budget-friendly and won’t hold water like untreated rip-stop nylon*
* If you are going to pick a sleeping bag with a rip-stop nylon shell, make sure that it is treated with a durable water repellent (DWR) coating.
Message from the Field Lab: DWR coating forms a hydrophobic (repels water) barrier along the fabric that causes water to bead and drip off, as opposed to soaking into the fabric. Don’t forget that DWR coating is water-resistant, not waterproof — think light drizzle, not full on monsoon.
Pro-tip: If the shell rips, it doesn’t matter how water-resistant it is — the water is getting in. The durability of rip-stop nylon makes it a popular choice if you’re willing to invest a few extra dollars.
The sleeping bag’s inner lining
The inner linings are also usually made of nylon or polyester. They come in brushed or taffeta. You can also get plain nylon (no thanks).
- Brushed: soft, cotton-like, has bed vibes
- Taffeta: smooth, breathable, soft but feels like gear
- Plain nylon: lightweight but plastic-y, does not have bed vibes
Stay away from absorbent fabrics like cotton. Once it gets wet, it is staying wet forever.
Choosing your bells and whistles
It’s like upgrading to first class but for sleeping on the ground! These are some sleeping bag features you might want to keep your eyes out for.
Temperature control
- Hood: keeps your head cozy
- Draft collar: blocks cold air from sneaking in around your neck
- Draft tube: blocks cold air from sneaking in along the zipper
- Insulated foot box: helps to keep your feet warm
- Foot vent: allows you to stick out your feet if it gets too warm
Zippers
- Two-way zipper: allows you to open the bag from top or bottom without fully unzipping
- Side or centre zipper: affects how you get in/out and partner compatibility
- If you are wanting to zip up with a partner, make sure that one bag has a right side zipper and that one has a left side zipper so that they can be zipped together!
- Zipper length: full length zipper = easier to get in and out; half length zipper = less cold air drafting in through the zipper
- Anti-snag zippers: stops fabric from getting caught in the zipper
Structural bonuses
- Internal stash pocket: for keeping glasses, headlamps, or snacks handy
- Pillow pocket (pillow sleeve): keeps your pillow in place
- Sleeping pad loops (sleeping pad sleeve): keeps your bag in place on your sleeping pad
- Hanging loops: makes hanging (for drying or storage) easier
Other things to consider…
- Is the sleeping bag’s shell water-resistant?
- Is the sleeping bag machine washable?
- Does it come with a stuff sack (i.e., a compression sack) for packing?
What features do you actually need?
If you only get to pick one feature, pick a sleeping bag with a draft tube. There is nothing worse than feeling a draft coming through the zipper. In my humble opinion, the other features are nice bonuses, but a draft tube is a non-negotiable for me.
The other features I would prioritize are a hood and a draft collar, but not to the same extent that I would prioritize a draft tube.
No draft tube = no thanks.
Don’t forget a sleeping pad!
Message from the Field Lab: When you sleep on the ground, your body heat transfers into the earth through a process called conduction — basically, your warmth is escaping into whatever you are touching. When you lay down in your sleeping bag, you compress the insulation underneath you. When the insulation is compressed, it can’t trap heat the way it is supposed to, and so you lose that heat to the ground. A sleeping pad can help with this by acting as a barrier that slows heat loss.
How to test a sleeping bag in store
- Climb in (no shame)
- Test the zippers… WHILE YOU ARE IN THE BAG!
- Check wiggle room (particularly around shoulders, hips, and feet)
- Try lying on your side and flail around a little
- Try out the features (e.g., does the hood fit?)
- How does the lining feel against your skin?
- Ask if you can try packing it in its stuff sack
Picking the perfect sleeping bag really hinges on when and where you plan to use it. The best sleeping bag is not the fanciest bag — it is the sleeping bag that keeps you comfortable on your adventures.
If you’re looking for more tips and tricks to help you get out of the inside and into the outside, consider signing up for my newsletter: The Trail Report!
