SurvivalistNestEnter your household and the number of days you want to cover. We will show exactly how many gallons to store, with a breakdown you can act on.
Get the free, printable 72-hour blackout plan, which includes a water section, a supply checklist, and a family contact sheet to go with the gallons you just calculated.
It multiplies the number of people by one gallon per day, adds a rough allowance for pets, applies your chosen number of days, and adds a buffer if you select hot climate or high activity. The result is a planning target, not a hard limit, so round up if you have the space. Water is the one supply you cannot easily improvise once the tap stops.
One gallon per person per day is the standard planning figure, covering drinking plus basic cooking and hygiene. This calculator uses that baseline and lets you add days, pets, and a hot-climate buffer.
Use at least three days for evacuation and two weeks for sheltering at home. The quick-set buttons cover three days, two weeks, and one month.
Yes, roughly. It estimates about 0.4 gallons per day for a dog and 0.08 for a cat as planning figures. Confirm your pet's actual needs with your veterinarian.