Free Preparedness Tool

Water Storage Calculator

Blue stackable water storage containers, barrels, and clear 5-gallon jugs organized in a garage for emergency preparedness

Water is the one thing you cannot improvise. Enter your household size, climate, and pets — get the exact number of gallons you need and what containers to buy.

Enter Your Household

Water is the one thing you cannot improvise. Tell us about your household and we'll calculate exactly how much water you need to store — broken down by drinking, cooking, hygiene, and pets.

Your Water Storage Estimate

Breakdown by use:

    Planning estimate only. Based on FEMA and Red Cross water storage guidelines. Actual needs vary by activity level, health conditions, and climate. In extreme heat, water needs can increase significantly — older adults are especially vulnerable to dehydration. Always store more than the minimum. Rotate stored water every 6–12 months.

    Common Questions

    How much water does a person need per day in an emergency?
    FEMA recommends a minimum of 1 gallon per person per day — half for drinking, half for sanitation. In hot weather or for physically active people, drinking needs can double to 1 gallon just for drinking. For seniors in summer heat in Florida or the Southwest, plan for 2+ gallons per person per day.
    What is the best way to store emergency water?
    Commercially bottled water is the safest and simplest option. For larger quantities, use food-grade plastic containers (look for HDPE with recycling code 2) or dedicated water storage barrels. Store in a cool, dark location away from direct sunlight and chemicals. Never use containers that held non-food products. Rotate every 6–12 months.
    Can I use tap water to fill storage containers?
    Yes. Municipal tap water is safe to store in clean, food-grade containers and will remain safe for 6–12 months. Add 1/8 teaspoon of unscented household bleach (6% sodium hypochlorite) per gallon if you want extra protection for longer storage. Well water should be filtered and treated before storage.
    How do I store water for my pets during an emergency?
    FEMA recommends 1 quart (0.25 gallon) per day for small pets and up to 1 gallon per day for large dogs. Store pet water separately and use the same rotation schedule as your human water supply. In extreme heat, pets need more water — watch for signs of dehydration: lethargy, dry gums, sunken eyes.
    Planning Estimate Only: Water storage recommendations are based on FEMA and American Red Cross emergency preparedness guidelines. Actual needs vary based on activity level, health conditions, climate, and individual circumstances. In extreme heat or medical situations, water needs can be significantly higher. Always store more than the minimum recommendation. Consult your physician about any medical conditions that affect hydration needs. In any emergency, follow official guidance from FEMA Ready.gov and your local emergency management authority. Franklyns Bay LLC assumes no liability for decisions made based on this tool. Full disclaimer →