Calculate your stored-water target
The one-gallon baseline comes from CDC guidance. Pet needs and margin remain household inputs.
What the result means
The CDC recommends storing at least one gallon per person per day for three days and trying for a two-week supply where possible. It also recommends more for pets, pregnancy, illness, and hot climates.
The calculator does not invent a universal pet allowance. Enter the daily total your veterinarian or trusted animal-care guidance recommends for your animals. The margin field can cover heat, illness, imperfect dispensing, or household-specific uncertainty.
Water weighs about 8.34 pounds per U.S. gallon. A large reserve should be split into containers that household members can safely lift and that the floor or shelving can support.
Use the number as a plan, not a promise
Three days is the floor
Use it as the first milestone, then add days and redundancy as space and budget permit.
Pet needs vary
Species, body size, diet, heat, illness, and medications change water needs. Enter your household value rather than using a generic guess.
Hygiene can exceed the baseline
The one-gallon baseline covers drinking and basic uses. A longer outage may require additional non-potable water for cleaning and sanitation.
Weight is a safety constraint
Distributed 3.5- to 5-gallon containers are often more practical than one large drum in apartments or upper floors.
Calculator basis
Guidance and specifications change. Follow the current local notice, official instructions, and exact model manual.