You’ve got your lists of what to have with you in an emergency. You’ve bought quite a few of the items. You’re all set to make a bug out bag (or three), but now you’re wondering, what is the best size for a bug out bag?
An ideal size for a bug out bag for a 72-hour emergency is 40 to 50 liters. More slightly built people, such as most women, should aim for 30 liters. For more long-term emergencies, especially when bugging out with small children, one will need a larger backpack of around 80 liters.
Obviously, quite a few factors play out when considering the best size for a bug out bag, so let’s take a look at them so you can make an informed choice about what is best for your needs.
Choosing A Bug Out Bag Size Depends On Your Needs
A key factor in choosing a bug out bag is one’s own size. You will want one that is fitted to the length of your torso and one that is not too heavy for you.
Selecting the right size of pack depends not only on your size but also on the weight you are carrying, which roughly corresponds to the length of the emergency.
In general, aim for 10 liters per 24 hours, with the caveat that if you are stronger and fitter, you can get away with 5 liters extra per 24 hours. Leave storage space in your pack to include items you find along the way, whether water, food, or clothing.
This results in the recommendation of a 40 to 50 liter pack for a 72-hour emergency.
For more long-term emergencies, you will need a larger pack. Bear in mind that a fully-loaded backpack should not exceed more than 25% of your body weight and that you should practice walking with your pack. Ensure that you have the fitness to carry it as far as necessary!
As a general sizing guide:
- Day packs are under 40 liters
- Weekend packs are 40 to 65 liters
- Week-long packs are 65 – 95 liters
- Expedition packs are over 95 liters
Do not select a pack that is too big. You will be tempted to fill it too full, which means too heavy to move quickly. In an emergency, being able to move quickly is worth more than some extra “nice to have” stuff.
You need to be able to move on foot. Riots and blocked roads may require you to part company with your vehicle, or you may run out of gas. Do not rely on a vehicle to bug out, which means not creating a pack so bulky and heavy that only a vehicle can comfortably move it.
A larger pack will also be tougher to stow and to grab in a hurry.
What’s more, a big pack makes you an obvious target for opportunists, as you are obviously carrying a nice lot of goodies! Resist the temptation to pack too much by using a smaller pack.
Pack all the essentials you need, but remember that knowledge trumps tools and knowledge weighs nothing. Having the skills to use a few multi-purpose tools is much better than lugging a load of specialized equipment around.
However, there are certain circumstances under which you may need to carry a larger pack, such as if you are bugging out with small children who cannot carry their own packs. In this case, you will need a larger, week-long or expedition pack. Make sure you are fit enough to carry it for as long as is necessary.
Your particular environment, needs, and likely emergencies will dictate what your bug out bag should contain, which will influence size.
Testing A Pack Before Buying It
Despite the process for measuring backpack capacity having long been standardized, we still find that two packs with the same claimed capacity do not hold the same amount of gear.
According to the standard for measuring pack capacity, measurements should not include any compartments not entirely sealed by zips. However, some manufacturers may be counting the capacity of these compartments, such as bottle holders and shovel pockets, toward the total capacity.
This means that comparing packs online is not as easy as testing packs out in person. Testing in person also allows you to carry the pack around and see how it feels to wear it.
Ask the salesperson to load some gear in, and carry it around the shop. This will give you an idea of whether you can handle the weight and whether the pack will hold enough for the emergencies you are preparing for.
How To Size Your Pack
In sizing a pack, the most important thing is not the length of your body but the length of your torso.
To measure your torso correctly, measure from your C7 vertebra at the top of your shoulders down to the top of your hip bones.
As a general guide:
Also, measure your hips from hipbone to hipbone, as this is where the hip belt rests. A pack that sits too high or too low will affect your gait and slow you down or even injure you.
The Impact That Lightweight Gear Has On Pack Size
Some things cannot be made more lightweight. One should pack around one gallon (2 liters) of water per adult per day. The same thing applies to food: one needs a minimum of 3500 calories for an adult per day, assuming they are expending a lot of energy, which is a safe assumption in a survival situation.
However, if you know how to build a shelter, you won’t need to lug a tent. If you know how to build a fire, you won’t need to lug a stove. Leaving out these two pieces of gear can trim 5 – 8 lbs from your pack weight, as well as reducing the size of pack you need.
As soldiers say, “Ounces equal pounds, and pounds equal pain.”
It is definitely in your survival interests to investigate the world of lightweight and ultra-lightweight backpacking.
Lightweight backpacking is outside the remit of this article; suffice to say that a base weight of 10 pounds, plus about the same weight of consumables, results in a lighter and smaller pack.
Appalachian Trail thru-hikers have developed some nifty hacks for reducing pack weight and size, such as storing small items in a Ziploc bag rather than something heavier and bulkier.
We can conclude that the best size for a bug out bag is one that you can easily carry while still providing you with what you need to make it through the emergencies you may face.
Because different people have different builds, a bag should be selected that is not too large for the person who will carry it and comfortably fits their torso length and hips.
It should also be big enough to hold what you will need to get through the emergencies that may face you in your particular part of the country while being light enough to enable you to move quickly.