Emergency Water Supply Calculator + Printable Storage Checklist
Calculate your household’s emergency water supply in US gallons and…
Calculate your household’s emergency water supply in US gallons and liters, then print your plan and storage checklist.
Start with at least 1 US gallon per person per day for 3 days; work toward two weeks if possible. This is a basic reserve for drinking and other essential uses, not a fixed drinking prescription. Source: CDC emergency water guidance.
Before Things Fail — My water plan
Your planned supply
Results are rounded up to the next tenth. Buy or fill enough containers to meet or exceed this volume.
This is a starting storage plan. Pet and extra allowances are included only when entered. Follow local emergency instructions and individual medical or veterinary advice.
Storage checklist
- Choose food-grade containers with tight lids; never reuse chemical containers.
- Clean and sanitize reusable containers before filling with safe water.
- Label each container with its capacity, filling date, and replacement date.
- Store in a cool place away from sunlight and chemicals.
- Replace self-filled water every six months; follow package dates for bottled water.
- Check for leaks and make sure someone can safely lift each filled container.
Container log
Write the actual amount stored and its unit. Use a separate row for each container or batch.
| Container / location | Amount + unit | Filled on | Replace / package date |
|---|---|---|---|
Source: CDC, “How to Create an Emergency Water Supply” (June 27, 2025). Guidance checked September 12, 2026. beforethingsfail.com
Calculate, print, prepare
Enter your household size and days, add any pet or extra water, then select Calculate my supply. Choose Print my plan to print the total, checklist, and blank container log. Add a filling date for a six-month replacement reminder for self-filled water; follow package dates for bottled water.
Example: Four people for three days need 12 US gallons (45.5 liters rounded up), before pet or extra allowances. The calculation uses 3.785411784 liters per US gallon.
Limited space? See how to store emergency water in a small apartment for practical ways to fit your calculated supply at home.
Need more detail? Read our water quantity guide, container guide, or water treatment guide.
Based on CDC emergency water guidance, checked September 12, 2026. Inputs stay in your browser and are not saved by this tool. Analytics may record use of the Calculate and Print buttons without your entered values.