Short answer: Ready.gov advises storing at least one gallon of water per person per day, for drinking and sanitation. A family of four covering three days needs at least 12 gallons, and a week needs at least 28. Ready.gov asks for “several days” and does not set one number of days, so pick the days that fit your risks.
| People | 3 days | 7 days | 14 days |
|---|---|---|---|
| 1 | 3 | 7 | 14 |
| 2 | 6 | 14 | 28 |
| 3 | 9 | 21 | 42 |
| 4 | 12 | 28 | 56 |
| 5 | 15 | 35 | 70 |
| 6 | 18 | 42 | 84 |
The basis, and what it leaves out
- Water: Ready.gov’s water page tells households to store at least one gallon of water per person per day for several days, for drinking and sanitation. This calculator multiplies exactly that. It does not add water for cooking, washing or flushing beyond what that gallon covers.
- Pets: Ready.gov’s pet page says to store a water bowl and several days of water and food for pets. It gives no amount, so the tool leaves pet water at zero until you enter your vet’s figure.
- Food: Ready.gov’s food page asks for a several-day supply of non-perishable food and gives no per-person amount. We therefore count meals only. Food storage for people with special diets, babies or medical needs is a question for a doctor or dietitian.
- Wording: Ready.gov changes its pages, so read the current text at the links above. Our summary of them is a paraphrase, not a quotation.
Turning gallons into containers
Divide the gallons by the container size and round up. Our water storage container picks list sizes and weights, and a full 7-gallon jug is heavy, so store several smaller ones if you cannot lift it. If you need to treat water, see emergency water filters . For power-dependent items such as a refrigerator, use the power station runtime calculator .