What you think you can carry and what you actually can carry are usually two different things. Typically, you should be able to carry 25 percent of your body weight in a pack. This of course assumes you are relatively fit. Some simple math calculations will tell you how much you should be able to carry. Of course, there are numerous factors involved, so the only way to know what you can actually carry for any distance is by going out and doing it.
Water weighs roughly 8.5 pounds per gallon (3.8kg), and water needs to be a priority so start there. A gallon a day for 72 hours means you are already at 25lbs plus in your pack starting out. You can cut this amount in half if, you have the means to collect, filter and purify a water source along the route.
There of course has to be a water source you can collect from, so planning is important. You need to know there are sources along your bug-out-route. Good planning means you can adjust the volume of water, to reduce the initial weight in the pack. Water will be consumed reducing weight, but also remember you will have to replenish your water supply so consider water a fixed weight. Once a bottle is empty, it needs to be refilled and carried with you as you move on from water sources.
Canned foods are heavy and they take up space, so they are not recommended for backpacks. Meals Ready to Eat (MRE’s) are ideal because they can be eaten from the package. They are fully contained meals, and they are lightweight and they do not require special openers like canned goods would. Keep things simple and use what you know works, remember you are not heading out on vacation.
People tend to over complicate things, they over analyze and dither and waffle over the simplest of things. Put MRE’s in the pack and move on, simple right?
There is debate on carrying extra clothing, because on one hand, everyone likes clean clothes and clean clothes are better insulators against the cold but on the other hand, clothing is heavy. You do need extra socks and underclothes, so put them with water, a must have in other words.
You will need clothing for the seasons and for the changing of the seasons but really how long do you expect to be wandering. If it is cold out when you leave then your winter clothing should be worn. Assume the weather where you end up at is similar to the weather you left behind because you are on foot and exactly how far do you think you can walk in three days. In some situations, it may take a day or even longer just to get clear of a large city that has collapsed because of a disaster.
Secure a heavy coat to the outside of the pack and have gloves, hats and scarves inside the pack but otherwise you can forgo extra jeans, extra heavy shirts and so on if weight is going to be a factor.
Lace your cold weather boots together and hang them off your pack or simply wear them. Extra shoes/boots are nice, but again you have to prioritize. What you may think you would need could fill a pickup bed. You have to separate need from want and face reality, you cannot bring it all with you.
Having the means to make a shelter is important, but keep in mind you are not heading off to some campsite, you will be on the move and you may only shelter in one place for a few hours, until you do get to your pre-determined safe haven. Tents are nice but do you have the room in your pack and do you really want to be caught inside a tent if your camp is overrun.
Tarps, ponchos, and even Mylar survival blankets can be temporary shelters and they can easily be packed or secured to the pack.
Tents are ideal for base camps, and if you do not have a base camp already planned for ahead of time, with supplies already there what then are you doing wandering around. Are you hoping to stumble upon one? This is why bugging-out has to be planned for, and it will take months to put together a livable plan, because you have to “live the plan” first to make sure it works.
Water, food, some clothing, shelter, fire/energy and then add medical supplies, illumination, cutting tools such as a hatchet/ax/machete, multi-tool, cordage, blanket or poncho liner and/or sleeping bag and so now you probably have more than you can carry. You will need a fixed bladed knife, personal protection, portable radio, extra batteries and well we can stop here because your bag is now full, probably to full.
Do You Really Need To
Bugging out is a last resort attempt to save your life, so it is not for the faint of heart, it will be grueling, and in some cases, it may even put you in a worse situation? Some may even call bugging out an act of desperation, but only you can decide that, because it may be the only option available during certain situations.
Bugging out is temporary and should be planned that way. Either you will be able to return home or you have taken up residency at another location, meaning you will need shelter and resources stockpiled at another location. In other words, you cannot just wander for days on end hoping for a solution, you need a plan before you have to leave.
The items in your bag either gets you there or gets you back, again simple, so do not over complicate it. Those that think they can head off with their bag and survive by their wit and wisdom for weeks or months on end had better plan a little better, because it is not happening.
The reality is bugging-out is not ideal, and is not recommended unless you do have a place to bug-out to and a way to get there that does not take days of walking. If you have to bug-out with no place to go you will have to remain close to populated areas in hopes that emergency aid organizations get up and running, but if they are able to get up and running then you probably did not have to bug-out to begin with. However, it is something you should consider. Populated areas for the time being will be where the needed resources are. Unless of course you have a safe haven that has shelter and supplies.