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Emergency prep

Water first. Know how much to keep at home.

Plan on 1 gallon per person per day: 3 days at minimum, 14 days if you can. Enter your household to get gallons, containers and a date to refresh it.
Work out my waterHow to store it

Figures checked against CDC, FEMA and Ready.gov.

Your household, your water

2. How many days

Water to store

28 gallons

  • People: 28 gal (2 x 1 gal x 14 days)

That fills about

  • 28 1-gallon jugs
  • 6 5-gallon jugs
  • 4 7-gallon jugs
  • 1 55-gallon drums

Refresh date

Empty and refill water you bottled yourself every 6 months.

The 6-month rule is for water you bottle yourself. Keep store-bought water sealed in its original bottles and use it by the date on the label.

Where the numbers come from

Gallons = people x 1 gallon x days. CDC, FEMA and Ready.gov all use 1 gallon per person per day. That covers drinking plus some cooking and washing: FEMA says a normally active person needs to drink at least half a gallon a day, and the rest goes to food and hygiene.

CDC sets the minimum at 3 days and asks you to try for a 2-week supply; FEMA says to consider at least two weeks. Ready.gov says water needs can double in very hot temperatures, so the hot-weather box doubles the per-person figure.

No agency gives an amount for pregnant, nursing or sick people, or for pets. They only say to store more. So the calculator adds nothing for them unless you type a number in. That is on purpose: we would rather you choose than trust a figure we made up.

How to store it

  • Use food-grade water storage containers. Never use a container that held bleach, pesticides or other chemicals (CDC).
  • Sanitize containers first with a solution of 1 teaspoon of unscented bleach in 1 quart of water (CDC).
  • Keep water somewhere cool, 50 to 70 F, out of direct sunlight (CDC).
  • Label each container with the date you filled it, and replace it every 6 months.
  • If supplies run low, FEMA says never ration water: drink what you need today and look for more tomorrow. Make stored water safe again with our bleach and boiling guide.

Treat what you collect

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Stored water is the plan. A purifier is the backup for when it runs out and you must use rain, creek or well water of unknown quality. Look for a purifier claim, not just a filter: see emergency water filters ranked by certification. Gravity purifiers we cover come from MSR (opens in a new tab) and LifeStraw (opens in a new tab), and a one-person press bottle from Grayl (opens in a new tab).

For vans and RVs, see Camper Volts.

Frequently asked questions

How much water should I store per person for an emergency?

At least 1 gallon per person per day, for drinking and sanitation. CDC says to store at least 3 days' worth and to try for a 2-week supply. For one person that is 3 gallons at minimum and 14 gallons for two weeks.

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

56 gallons: 4 people x 1 gallon x 14 days. That is 12 five-gallon jugs. The 3-day minimum is 12 gallons. Store more in very hot weather (Ready.gov says needs can double) and for anyone pregnant, nursing or sick.

How often should I replace stored water?

Replace water you bottled yourself every 6 months (CDC, Ready.gov). Keep store-bought water sealed in its original bottles and use it by the date on the label (CDC, FEMA). Store all of it somewhere cool, 50 to 70 F, out of direct sunlight.

How much water do pets need in an emergency?

CDC lists pets among those who need extra water, but no government agency gives an amount. Ask your vet, or measure what your pets drink on a normal day, and enter that in the calculator.

What containers can I use to store water?

Food-grade water storage containers are best. CDC says otherwise use a durable, unbreakable container (not glass) with a tight cap, ideally with a narrow opening, and never one that held chemicals such as bleach or pesticides. To sanitize a container, CDC says to use a solution of 1 teaspoon of unscented bleach in 1 quart of water.

General information for home emergency planning, not medical advice. Follow instructions from your local health department and emergency officials. See our disclaimer.

Sources

  1. CDC, Creating and Storing an Emergency Water Supply — 1 gallon per person per day for 3 days; try for 2 weeks; sanitize, store at 50-70 F, replace every 6 months
  2. FEMA, Food and Water in an Emergency (PDF) — drink at least half a gallon a day; store 1 gallon per person per day; consider at least two weeks; never ration
  3. Ready.gov, Water — in very hot temperatures water needs can double; replace non-commercial water every six months

Keep going

Photo: Devon MacKay on Unsplash (Unsplash License).