The constraint nobody puts on the checklist
Every emergency kit list is a list of things. None of them are lists of weights, and weight is the property that decides whether the kit does its job. A bag that stays by the door because nobody can lift it, or that gets set down two hundred yards along the road, has protected nothing. This calculator exists to put a number on that before the day it matters rather than after.
The arithmetic is simple and the result is usually unwelcome. Take the ordinary contents of a household go bag, add a couple of gallons of water, add the weight of the bags themselves, and the total lands somewhere in the sixties of pounds for a family of four. That is carryable if the four people carrying it are four adults. It is not carryable if two of them are children, which is the situation most households are actually in.
What a person can carry
Carried load is limited by the person, not by the bag, and there is no single correct figure. The proportion used as a default here is 20 percent of body weight, which is a rough planning convention for an ordinary adult carrying a load a short distance on foot. It is an input rather than a constant because the honest answer varies with fitness, age, the pack, the terrain, the distance and whether the person has a back or a knee that objects. Anybody with a relevant health condition should be working from what their own clinician says rather than from a percentage.
| Carrier | At 20% of body weight | What that actually buys |
|---|---|---|
| Adult, 180 lb | 36 lb | A real share, minus a 2 to 3 lb pack |
| Adult, 145 lb | 29 lb | A real share, and noticeably less than the first adult |
| Teenager, 110 lb | 22 lb | Their own things and a little of the shared load |
| Child, 60 lb | 12 lb | Their clothes, a bottle, and something they care about |
The last row is where the plan usually breaks. On paper a child contributes 12 pounds of capacity. In practice a child on a difficult day carries their own comfort items and nothing else, tires quickly, and may need carrying themselves. Plan the load as though the children carry nothing shared, and if it still works, you have margin.
Water is the line that dominates
At 8.34 pounds a gallon, water is almost always the heaviest single entry in a kit, and it is the entry that most often pushes a workable kit over the edge. Two gallons is under 17 pounds, which sounds trivial until it is a quarter of the total load. Three days of drinking water for a family of four is over a hundred pounds and is not going anywhere on foot under any circumstances.
The resolution most households arrive at is a split: a small amount carried, a larger amount in the vehicle, and the bulk of the household supply staying at home where it was always going to stay. Work the household quantity out with the emergency water storage calculator, then decide deliberately which part of it travels, rather than discovering the answer while loading a car.
Reading the split, and the part where the arithmetic is wrong
This page divides the load in proportion to each person capacity, which is the fairest mechanical split and is not the split any real household uses. Real kits are packed by function: the person most likely to be separated carries the documents and the phone charger, the person with the children carries the least, and the tools go with whoever will use them. Use the proportional numbers as a ceiling check on each person rather than as packing instructions.
The other thing the arithmetic hides is that a kit is not one bag. Splitting it across the house, the vehicles and a small bag by the door is what makes it survivable, because different emergencies give you different amounts of notice. Fifteen minutes of warning gets you the bag by the door. An hour gets you the bag and the vehicle load. A day gets you most of the house. Design for the fifteen minute case first, and the evacuation timing planner shows exactly how little fifteen minutes is once loading a family into a vehicle is counted honestly.
The failure mode this is trying to prevent
Over-packed kits fail in a specific and predictable way. They are built once, weighed never, stored somewhere awkward, and then on the day they are either left behind entirely or taken as far as the driveway. The thing that prevents it is not a better bag. It is a shorter list, a weighed total, and one rehearsal in which somebody actually picks the thing up and walks to the end of the street with it. That rehearsal takes ten minutes and it changes what is in the bag every time.
What goes in it is a separate question from what it weighs, and the contents side is covered in the family emergency plan, along with the documents, the medication list and the out-of-area contact that matter more than any piece of equipment. Hazard-specific kit differences are worth checking too: what a kit needs in a hurricane is not what it needs in a severe cold event, and warm layers weigh considerably more than the summer equivalent.
Questions people ask
How heavy should an emergency kit be?
Light enough that the person carrying it will actually leave with it, which is a lower number than most lists produce. A common planning convention for a load carried on foot over a short distance is around 20 percent of body weight, so roughly 30 to 36 pounds for an average adult including the pack itself. That is a rough proportion rather than a rule, and it should come down for anyone with a back, knee or heart condition, for longer distances, and for children. The test that settles it is picking the bag up and walking to the end of the street.
Why does the water dominate the total?
Because water weighs 8.34 pounds a gallon and there is no way around that. Two gallons is nearly 17 pounds, and a genuine multi-day supply for a family runs to hundreds of pounds, which no household carries on foot. This is why almost every workable plan splits water three ways: a small amount in the carried kit, a larger amount in the vehicle, and the bulk staying at home. Decide that split deliberately using the household figure from the water storage calculator rather than discovering it during a loading.
Should children carry part of the kit?
Their own clothes, their own bottle and something that matters to them, and beyond that plan as though they carry nothing shared. On paper a 60 pound child contributes 12 pounds of capacity; in practice a tired or frightened child carries less than that and may need carrying themselves. Giving a child their own small bag has real value, but the value is that it is theirs and it holds their things, not that it takes weight off an adult. Build the load so it still works if every child contribution is zero.
Is one big kit better than several small ones?
Several, in different places, is what survives contact with a real event. The amount of notice you get is what decides which one you use: fifteen minutes gets the bag by the door, an hour gets that plus whatever is already in the vehicle, and a day gets most of the house. A single large kit is optimised for the case that gives you the most time, which is the case you least need optimising for. Split it, and make sure the smallest one is the one that can leave immediately.
What happens if the total is over what the group can carry?
Take things out, and take out the heaviest things first rather than the ones you care least about, since that is where the pounds are. This page lists the heaviest lines in order for that reason. The alternative fixes are moving the excess to a vehicle, splitting the kit so the heavy part stays home, or reducing the water carried, which is usually the largest single lever. What does not work is deciding to carry it anyway, because an over-packed kit is put down at the first hill and then nobody has anything at all.