How Much Water Should You Actually Store Per Person?
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The number FEMA and the Red Cross both land on is one gallon of water per person, per day. It sounds low for a household that goes through far more than that at the tap — but the figure isn't meant to replicate normal water use. It's a survival minimum: enough to keep someone hydrated and reasonably clean when the tap has stopped.
Both agencies break that gallon down the same way: about two quarts for drinking, and two quarts for food preparation and hygiene — brushing teeth, washing hands, rinsing a dish. It is a floor, not a comfort level, and both agencies say so explicitly: individual needs vary with age, health, activity, and climate.
How long a supply should last
Ready.gov's standard target is a three-day supply per person as the minimum for a household kit, with a two-week supply — 14 gallons per person — recommended where storage space allows. The three-day figure maps to the window most short-notice disasters (storms, grid failures, boil-water advisories) resolve within; the two-week figure covers a slower or larger-scale disruption, where municipal restoration or resupply takes longer.
When the baseline isn't enough
The one-gallon figure assumes a healthy adult at rest in a temperate climate. Both the CDC and the Red Cross flag several conditions that push real need higher, and none of them are edge cases in a genuine emergency:
| Factor | Adjustment |
|---|---|
| Hot climate | Up to double the baseline — CDC guidance puts high-heat needs around two gallons per person per day |
| Physical exertion | Increases fluid loss beyond the resting baseline; factor in if evacuation on foot or manual labor is likely |
| Pregnancy or nursing | Higher water needs; plan above the standard gallon |
| Illness, fever, or conditions like diabetes and kidney disease | Increased hydration needs — check with a provider on a realistic number |
| Pets | Roughly one ounce of water per pound of body weight, per day, in addition to household totals |
Adjustments are directional guidance from CDC and Red Cross materials, not fixed multipliers — plan conservatively rather than to the exact minimum.
None of these stack neatly into a single formula, which is the honest reason neither agency publishes one. A household with a toddler, a dog, and a Gulf Coast summer is not the same planning problem as one healthy adult in a mild climate — the one-gallon figure is a starting point to multiply and adjust from, not a number to stop at.
"Store at least one gallon of water per person per day for several days, for drinking and sanitation — and consider storing more for children, nursing mothers, people who are sick, and anyone in a hot climate."
What actually counts as "stored"
Commercially bottled water is the simplest option and needs no rotation schedule within its printed shelf life. Water stored in food-grade containers filled at home should be rotated roughly every six months. Either way, the gallon figure assumes water that's actually reachable without power or a working tap — stored separately from, not instead of, a plan for purifying water from other sources if the stockpile runs out.
References
- Ready.gov / FEMA. "Water." Build a Kit / Emergency Supply List.
- American Red Cross. Emergency Preparedness Kit Checklist.
- CDC. "How to Create an Emergency Water Supply."
A Survival Codex device won't replace stored water, but it holds the purification, dosing, and illness-response references worth having once the easy gallon is gone. See the device →
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Generated with AI assistance and reviewed for accuracy. Always verify critical survival information against additional sources.