Emergency water calculator
How much water should you set aside for an outage? Choose your household and duration for a clear storage plan in liters.
No account · No tracking · Calculated in this browser
Example: 2 people, 3 days. Change the fields to calculate your supply.
Your supply plan
27.36 LFor 3 days · 2 people · including your chosen buffer
- Adults — full period
- 22.8 L
- Children — full period
- 0 L
- Daily household storage
- 7.6 L
- Storage for selected period
- 22.8 L
- Drinking allocation (assumption)
- 12 L
- Other uses within this supply
- 10.8 L
- Additional buffer
- 4.56 L
This is a storage plan, not a medical drinking target. Account separately for pets, hot weather and individual needs.
What does this estimate include?
People × days × liters per person per day. The default 3.8 L includes drinking and other basic uses, not just beverages. Children do not automatically receive a smaller allowance. Choose 24 hours, 72 hours, 7 or 14 days, or a custom period. One day is a calculation option, not a recommended preparedness target.
Drinking, cooking and hygiene
The 2 L drinking allocation is an editable example, not a medical minimum. It is already part of the total. Heat, illness, pregnancy and pets can require more water. Full washing, toilet flushing and cooking dried foods may need a separate plan.
Containers and rotation
CDC recommends at least a gallon (about 3.8 L) per person per day for 3 days, and a 2-week supply if possible. Choose bottled water or clean food-grade containers. Never reuse chemical containers. Replace home-filled water every 6 months; follow the manufacturer’s date for bottled water. Label fill dates and store away from heat, sunlight and chemicals.
Connect your result to a plan
Sources and scope
Strongstead tools help with planning. Follow local emergency instructions and individual health advice. Sources for the guidance:
Strongstead · https://strongstead.com/tools/emergency-water-calculator/