Water storage basics: how much to keep, what to keep it in, and when to replace it

How much: multiply people by days

Ready.gov and the CDC give the same figure: at least one gallon per person per day, for drinking and basic sanitation. The CDC adds that you should store more for pregnant women, for anyone who is sick, for pets, and if you live in a hot climate.

• 2 people: 6 gallons for 3 days, 28 gallons for 2 weeks.
• 4 people: 12 gallons for 3 days, 56 gallons for 2 weeks.
• 6 people: 18 gallons for 3 days, 84 gallons for 2 weeks.

Water weighs about 8.3 pounds a gallon, so 56 gallons is around 470 pounds. Measure the shelf or the floor space before you buy containers. Our free household water plan does the count for your own house, pets included, and prints as a worksheet.

What to keep it in

The CDC's advice is to use FDA-approved food-grade water storage containers, which camping and surplus stores sell. Do not reuse a container that ever held a toxic liquid or solid, such as bleach or pesticide. Pick a size you can lift when it is full: a 5-gallon jug weighs about 42 pounds.

Clean the container before you fill it

These are the CDC's steps:

1. Wash the container with soap and rinse it completely.
2. Mix 1 teaspoon of unscented liquid household chlorine bleach into 1 quart (4 cups) of water. The bleach label should read 5% to 9% sodium hypochlorite.
3. Pour the mix in, close the lid tightly and shake so it touches every inside surface.
4. Wait at least 30 seconds, then pour it out.
5. Let the empty container air-dry, then fill it with clean water and close the lid tightly.

Where to keep it, and when to replace it

Keep containers somewhere cool, between 50°F and 70°F, out of direct sunlight and away from gasoline, pesticides and similar products. Write "drinking water" and the fill date on each one. If you filled the containers yourself, replace the water every 6 months. Tie it to a date you already keep, like the two clock changes. Store-bought bottled water follows the date printed on it.

Four mistakes that cost people their supply

• Counting only drinking water. Cooking, pets and basic cleanup come out of the same gallons.
• Buying containers before measuring the space they have to live in.
• Keeping everything in one spot, such as a garage that reaches 100°F in summer.
• Filling the containers once and never writing the date down.

When the stored water runs out

Stored water buys you days. For what comes after, a tank water heater already holds 30 gallons or more in most American homes, and this free tool counts what your house already holds. If you have to drink water you are not sure about, the filter, treat and test guide gives the federal bleach dose for the container in front of you.

Sources: CDC, "How to Create an Emergency Water Supply", page dated 27 June 2025. Ready.gov, "Water". Both read on 20 September 2026. The weight of water and the household totals are our arithmetic.