Tool

Supplies calculator

How much water and food your household needs, based on how many of you there are and how many days you want to cover. Your data never leaves your browser.

How we calculate

  • Water: 1 gallon (about 4 liters) per person per day, the standard reference in expert guides: 2 to 3 liters for drinking and the rest for cooking and basic hygiene. In hot weather, an extra liter.
  • Pets: about 1 fluid ounce per pound of body weight per day. A medium dog needs around a third of a gallon and a cat about a cup.
  • Food: 2,000 calories per adult and 1,400 per child per day.
  • Weight: estimated at about 2 calories per gram, the average of a pantry that mixes canned food, heavy because of its water, and dry goods like rice, pasta or nuts.
Water by number of people and days
People3 days1 week2 weeks1 month
13 gal7 gal14 gal30 gal
26 gal14 gal28 gal60 gal
39 gal21 gal42 gal90 gal
412 gal28 gal56 gal120 gal

From a month on, storing all your water stops being practical: store two weeks and add a filter and an alternative source. See the water guide and the long-term preparedness guide.