How much water should you store?

Enter your household and how long you want to be covered. The numbers come straight from the water and food chapters of The Off-Grid Survival Handbook: one gallon per person per day as the minimum, two to three gallons once you cook and keep clean, and 2,000 calories per adult per day in the pantry.

People in the household

Everyone who drinks water

Adults

The book gives calories per adult

How long to cover

The book's stay-or-leave test uses 2 weeks

Minimum water

56 gallons

about 212 liters, 1 gallon per person per day

With cooking and sanitation

112 to 168 gallons

about 424 to 636 liters, 2 to 3 gallons per person per day

Your first step this week

12 gallons

3 gallons per person, the book's week-one target

Pantry for the adults

56,000 calories

2,000 calories per adult per day

Storage: for up to 2 weeks, bottled water or food-grade containers work, rotated every 6 to 12 months.

Without JavaScript: multiply people by days for the minimum gallons, then by 2 to 3 for cooking and sanitation. One gallon is about 3.785 liters. Adults times days times 2,000 gives the pantry calories.

How the numbers work

Minimum: 1 gallon per person per day, for drinking and basic hygiene. The book rounds a family of four to about 30 gallons a week.
Comfortable: 2 to 3 gallons per person per day once cooking, sanitation, and a little gardening are included.
Food: 2,000 calories per adult per day, the rule of thumb for the 30-day emergency pantry.
Why two weeks matters: the stay-or-leave rule in chapter 3 asks whether you have water, food, and shelter for two weeks or more. If you do, staying home is sustainable.

Treat the result as a baseline, not a ceiling. The book is clear that families need more, especially with children, pets, or medical needs. This page is for general preparedness information only and is not medical advice.

Where to keep it

1 to 2 weeks: bottled water or food-grade containers. Rotate every 6 to 12 months.
2 to 6 months: 55-gallon barrels or water bricks, in a cool, dark place.
6 months or more: rainwater catchment, underground cisterns or large tanks, or a well with a hand pump or solar pump.

Storing water is only half of it. The handbook also covers the difference between filtering and purifying water, and why you filter first and then purify.

The full plan

The Off-Grid Survival Handbook

Water is week one. The book's 30-day starter plan goes on to food, energy and home backup, then family and community, with Quick Wins and a checkpoint at the end of every chapter.

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Frequently asked questions

How much water should I store per person?

At least one gallon per person per day, for drinking and basic hygiene. The Off-Grid Survival Handbook calls that the minimum and suggests two to three gallons per person per day once you include cooking, sanitation, and gardening.

How much water does a family of four need for two weeks?

At the one gallon minimum, 56 gallons, about 212 liters. With cooking and sanitation at two to three gallons per person per day, 112 to 168 gallons.

How should I store emergency water?

For one to two weeks, bottled water or food-grade containers, rotated every 6 to 12 months. For two to six months, 55-gallon barrels or water bricks kept in a cool, dark place. For longer than six months, rainwater catchment, cisterns or large tanks, or a well with a hand or solar pump.

Does the calculator include pets or medical needs?

No. It uses the per-person baseline only. The book notes that families need more, especially with children, pets, or medical needs, so add a margin on top if that is your household.