How Much Emergency Food and Water Does a Family Need?
Plan on roughly 4 litres (1 gallon) of water per person per day and 1,500–2,000 calories of shelf-stable food per person per day. That means a family of four should hold about 48 litres of water and three days of food as a minimum, and work toward two weeks. What matters just as much as the amount: knowing how many days your current supply actually covers.
Water first
Water is the constraint in almost every household. The widely published planning figure is about 4 litres (1 gallon) per person per day — around 2 litres for drinking and the rest for cooking, medication and basic hygiene. Increase it for hot weather, illness, pregnancy, nursing, and anyone doing physical work. Pets need their own allocation.
A quick reference
- 1 person, 3 days — about 12 L
- Family of 4, 3 days — about 48 L
- Family of 4, 2 weeks — about 112 L
Storing it properly
Keep water cool, dark and off concrete floors, away from fuel and cleaning products. Rotate commercially bottled water roughly yearly and home-filled containers roughly every six months. Add at least one backup method — a filter, purification tablets, or plain unscented household bleach used at the dose your health authority publishes — because storage alone runs out.
Food that actually gets eaten
Aim for 1,500–2,000 calories per person per day of food that needs no refrigeration and little or no cooking. The best emergency food is food your household already eats, because it gets rotated naturally.
- Canned protein, beans, vegetables and fruit — pull-tab lids where possible
- Peanut butter, nuts, trail mix, energy bars
- Rice, pasta and oats, if you have a way to boil water
- Shelf-stable milk, instant coffee, electrolyte mix
- A few freeze-dried meals for variety and long shelf life
- Comfort food — morale matters more than people expect
- Infant formula, pet food and special-diet items, in their own allocation
Do not forget a manual can opener. It is the most commonly missing item in an otherwise good pantry.
Working out how long your supply lasts
The arithmetic is simple and rarely done. Total stored calories ÷ (people × daily calories) gives your food days. Total stored litres ÷ (people × daily litres) gives your water days. Your real coverage is the smaller of the two — a month of rice with three days of water is a three-day supply.
PanPrep does this continuously from your logged inventory, so days of supply update as you use and replace items rather than being recalculated by hand.
Rotation is the whole game
Almost every failed food and water store failed by expiry, not by disaster. Date everything as you buy it, shelve newest at the back, and review twice a year alongside your emergency supply inventory. PanPrep's expiration alerts exist because this is the step households skip.
Sources worth reading
The per-person figures above reflect long-standing public guidance from bodies such as the Government of Canada's Get Prepared program, the Canadian Red Cross, Ready.gov and FEMA. Check your local health authority for water disinfection instructions specific to your area, and follow official advice during an actual water advisory.
Common Questions
How much emergency water should a family store?
The common guidance from emergency management agencies is about 4 litres (1 gallon) per person per day — roughly half for drinking and half for cooking and hygiene. A family of four needs about 48 litres for three days, and roughly 112 litres for two weeks.
How much emergency food should I keep?
Plan at least a 72-hour supply of shelf-stable food per person, and build toward two weeks if you have the storage. Budget roughly 1,500–2,000 calories per person per day, more for physically active adults.
How long will my emergency supplies last?
That depends on household size, calories per item and how much water each person uses per day. Divide total stored calories by daily household calories, and total litres by daily household water use — the smaller of the two numbers is your real limit. PanPrep calculates both from your logged inventory.
Does stored water expire?
Commercially bottled water carries a best-before date and is generally rotated every 12 months. Home-filled containers should be replaced roughly every six months and stored cool, dark and away from chemicals or fuel.
Should I buy freeze-dried emergency food?
It is convenient and long-lived, but it needs water to prepare — which raises your water requirement. A mix of familiar canned and dry food plus some freeze-dried meals is usually more practical and cheaper than an all-freeze-dried store.