How to stockpile food and water for your household: what the official lists say

How much do official sources ask you to store?

Ready.gov's kit page says: "After an emergency, you may need to survive on your own for several days." Its basic kit lists "one gallon per person per day for several days" of water and "at least a several-day supply" of non-perishable food.

The CDC asks for at least 1 gallon of water per person per day for 3 days and adds: "Try to store a 2-week supply if possible." The American Red Cross sets out two tiers: a 3-day supply of water and food to take with you if you evacuate, and a 2-week supply for home.

So the range in official advice runs from several days to 2 weeks; the Red Cross's power outage page says to store food and water "for at least two weeks." None of the sources here sets a figure in months. Going further is your own choice, for reasons such as a rural home, a well pump or a medical need. Our 90-day blackout plan explains how to build further in stages if you want to.

Water: 1 gallon per person per day

Ready.gov says a normally active person needs about three quarters of a gallon of fluid a day, and that needs vary with age, health, activity, diet and climate. It also says: "In very hot temperatures, water needs can double." Children, nursing mothers and sick people may need more. The 1 gallon figure covers drinking and sanitation.

Here is what that comes to at 1 gallon per person per day. This is our arithmetic on the CDC and Red Cross figures, not a number any agency publishes. Add more for hot weather, pets and illness.

• 1 person: 3 gallons for 3 days, 14 gallons for 2 weeks
• 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

How to store water safely

Ready.gov advises buying commercially bottled water and keeping it in the sealed original container in a cool, dark place. If you fill your own containers, use food-grade water storage containers. The CDC says: "If you are filling containers with water to store, replace the water every 6 months." Ready.gov likewise says water that has not been commercially bottled should be replaced every six months.

Ready.gov says never to ration drinking water unless authorities tell you to. If your stored water runs out, the CDC says boiling is the best way to kill germs in water (it does not make water with fuel or toxic chemicals safe): bring clear water to a rolling boil for 1 minute (3 minutes above 6,500 feet), then let it cool. Our make water safe and how much water to store guides go through the steps, and if you do want containers, see our water storage comparison.

Food: a few days to 2 weeks, from foods you eat

Ready.gov's food page says: "Store at least a several-day supply of non-perishable food," and "Choose foods your family will eat." It suggests canned meats, fruits and vegetables, and says to include a manual can opener and eating utensils. It also says to remember any special dietary needs.

None of the official sources here sets a calorie target for emergency food. A practical way to start is to count meals: 3 meals a day for each person, for the number of days you want, then look at what your cupboards already cover. Our food storage calculator does the counting for your household and the non-perishable food list gives ideas that need no cooking.

Stock what keeps without a fridge, and plan for power cuts: Ready.gov says the foods should not require "refrigeration, cooking, water or special preparation." Ready.gov also notes that commercially canned food may be eaten out of the can without warming.

Keep the stockpile in date

Ready.gov says to maintain a kit after you assemble it: replace expired items as needed, and re-think your needs every year as your family changes. The easiest habit is to buy what you already eat, put the newest at the back and use the oldest first. That way nothing is wasted and the shelf stays current.

Store everything in one or two places you can find in the dark, along with a flashlight and a battery-powered radio. Our emergency food storage and emergency kit checklist guides cover the rest.

Medicines and the other basics

Food and water are only part of a kit. The Red Cross list also asks for a 7-day supply of medications and medical items, sanitation and personal hygiene items, copies of personal documents, and emergency contact information. Ready.gov adds a manual can opener, a whistle, and a battery-powered or hand crank radio.

If a family member relies on a medicine or a medical device, ask your prescriber and your pharmacy about extra supply, and our medical devices in a power outage guide covers backup power.