Count usable gallons or liters, account for individual needs, and separate supplies kept at home from water you can carry.
Begin with volume rather than cases
Multiply the number of people by a daily planning amount and the number of days. A case is not a consistent unit: bottle size and count vary. First total what you already have, then compare it with your plan.
CDC recommends at least one gallon per person per day for three days and, where possible, a two-week supply. This is emergency storage for uses including drinking and food preparation, not a medical instruction to drink that quantity daily. Allow for additional needs such as pets, illness, pregnancy, and hot conditions.
| People | Three-day baseline | Approximate liters |
|---|---|---|
| 1 | 3 gallons | 11.4 L |
| 2 | 6 gallons | 22.8 L |
| 3 | 9 gallons | 34.2 L |
| 4 | 12 gallons | 45.6 L |
The liter figures use 3.8 L per gallon as a rounded planning conversion. They do not include every household use, such as ordinary bathing and laundry. Apply individual needs and current local advisories.
Find the actual gap
If a four-person household has six one-gallon containers, it has six gallons against a three-day baseline of twelve. The starting gap is six gallons. Check that the stored water is suitable for its intended use before counting it.
Record usable water, target quantity, and the next replenishment action together. Water removed for a trip or placed in a go bag should not be counted twice in the home inventory.
Keep drinking water distinct from other water
Label water intended for drinking separately from water reserved for cleaning or flushing. Clear appearance does not establish safety. Follow your water utility or public-health authority’s specific advisory; different contamination problems require different responses.
Use appropriate food-grade containers, and follow official cleaning and filling instructions when preparing your own supply. Never reuse containers that held toxic chemicals. Follow labeled dates for commercially bottled water; CDC’s six-month replacement instruction applies to water you fill and store yourself.
Storage and evacuation are separate decisions
Several days of household water is heavy. Do not plan for one person to carry the entire reserve during evacuation. Work out a manageable carried quantity alongside the route, assistance needs, and official support information.
At home, consider shelf load, tipping, leaks, and access. Keep exits clear and avoid excessive heat and direct sunlight. Make sure the family knows which water is usable and where it is stored.
Keep a small private inventory
| Record | Fill in |
|---|---|
| People and additional needs | ___ |
| Planning days and target volume | ___ |
| Current usable volume | ___ |
| Gap and replenishment date | ___ |
| Earliest labeled date or refill date | ___ |
Common questions
Does a filter replace storage? It cannot solve a loss of supply and may not address the contaminant in an advisory.
Does three days cover every emergency? No. It is a starting baseline, not a promise about restoration time.
Do this today
- Convert bottle counts into total usable volume.
- Write the household target and gap.
- Separate drinking and non-drinking water labels.
- Add a realistic replenishment quantity to your shopping plan.
Reference: CDC emergency water supply guidance.