How much water to store for an emergency
Water is the supply you run out of first and the one people under-plan most. The good news: the math is simple, and once it is set up, keeping it fresh takes minutes.
The simple rule: one gallon per person, per day
The standard guidance from FEMA and the Red Cross is to store at least one gallon of water per person, per day. Roughly half is for drinking and half for cooking and basic hygiene. Treat it as a floor, not a luxury amount, so round up rather than down.
How many days should you cover?
Two numbers matter:
- 3 days is the minimum for a grab-and-go kit if you have to leave.
- 2 weeks is the target for staying home through a storm, outage, or supply disruption. Most agencies now recommend two weeks, because three days rarely matches how long real disruptions last.
Water storage chart
Using the one-gallon-per-person-per-day rule:
| Household | 3 days (go bag) | 2 weeks (home) |
|---|---|---|
| 1 person | 3 gallons | 14 gallons |
| 2 people | 6 gallons | 28 gallons |
| Family of 4 | 12 gallons | 56 gallons |
That covers drinking plus basic sanitation only. Add more for the situations below.
Who needs more
- Pets: roughly a gallon a day for a dog, less for a cat. Do not leave them out of the total.
- Hot climates and physical activity can double how much you drink.
- Children, nursing or pregnant people, and anyone ill need extra.
- Medical needs like home dialysis change the math entirely. Plan around them first.
What to store it in
From easiest to most involved:
- Commercially bottled water is the simplest and keeps the longest. Buy it sealed and leave it sealed.
- Food-grade water containers (5 to 7 gallon jugs, or stackable bricks) are good for larger home storage.
- Avoid old milk jugs. They are hard to fully clean, break down over time, and can leak or grow bacteria.
Keep it somewhere cool and dark, off bare concrete where you can, and away from gasoline or strong chemicals, since some plastics absorb odors.
Does stored water expire?
Water itself does not go bad, but the container and what grows in it can. Sealed commercial bottles carry a best-by date for taste and packaging quality, so replace them by that date. Water you bottle yourself should be rotated every six months.
The part people skip: keeping it fresh
Most water storage fails not on day one but a year later, when you find jugs you cannot remember filling. The fix is rotation: label every container with the date, use the oldest first, and refill to the back. Build it into a routine so it actually happens instead of living on a someday list.
Quick checklist
- One gallon per person, per day, minimum.
- Cover at least two weeks at home, three days to go.
- Add water for pets, kids, heat, and medical needs.
- Prefer sealed commercial water or food-grade containers.
- Label dates and rotate. Do not just stack and forget.