How much water should you store for an emergency, and how do you calculate household water needs?
Calculate your household reserve and make room to store it.
Published September 22, 2026
The direct answer
CDC says to store at least 1 gallon per person per day for 3 days and to try for a 2-week supply when possible. Store more for pregnant people, people who are sick, pets, or hot climates. Measure a cool, dark storage spot away from fuel or pesticides. Leave room to reach and rotate the containers.
Decision table
These totals use CDC's daily amount. The 7-day column is an intermediate planning step; CDC names 3 days and says to try for 2 weeks.
| Household Size | 3-Day Supply | 7-Day Supply | 14-Day Supply | Basis |
|---|---|---|---|---|
1 person | 3 gallons | 7 gallons | 14 gallons | 1 gallon per person per day |
2 people | 6 gallons | 14 gallons | 28 gallons | 1 gallon per person per day |
3 people | 9 gallons | 21 gallons | 42 gallons | 1 gallon per person per day |
4 people | 12 gallons | 28 gallons | 56 gallons | 1 gallon per person per day |
5 people | 15 gallons | 35 gallons | 70 gallons | 1 gallon per person per day |
6 people | 18 gallons | 42 gallons | 84 gallons | 1 gallon per person per day |
| Guideline Attribute | Stated Guidance |
|---|---|
Minimum stored-water baseline | At least 1 gallon per person per day for 3 days |
Plan for more when | Someone is pregnant or sick, pets are included, or the climate is hot |
Recommended containers | Commercially bottled water in original sealed containers, or food-grade containers |
Container sanitizing solution (DO NOT DRINK) | 1 teaspoon unscented 5% to 9% household bleach in 1 quart of clean water; coat the inside, wait at least 30 seconds, drain, and air-dry |
Tap water rotation interval | Replace home-prepared water every 6 months |
Boiling disinfection | Rolling boil for 1 full minute |
Bleach disinfection for clear water | Follow the label first; otherwise use 8 drops of unscented 5% to 9% household bleach per gallon and wait at least 30 minutes |
Source | CDC emergency water storage and treatment guidance |
Planning for 3 Days, 7 Days, or 14 Days
Short-Term Shelter-in-Place
Start with CDC's minimum: three days at 1 gallon per person per day. A spreadsheet does not put water on the shelf.
Extended Disruptions
Build toward two weeks as storage allows. Rotate the containers.
Gaps and Limits in Official Guidance
CDC says pets need additional stored water but does not set one universal amount for every animal.
For treatment, follow local health guidance and the product label first. CDC says boiling is best for germs. Chemical disinfectants do not work as well against some parasites, and no amount of boiling, bleach, or filtering makes water contaminated by fuel, toxic chemicals, or radioactive material safe.
Official Sources
Save these free CDC resources before an outage. Write the fill date on each container.
Frequently asked questions
How much emergency water should a household store?
CDC says to store at least 1 gallon per person per day for 3 days and to try for a 2-week supply when possible. Store more for pregnant people, people who are sick, pets, or hot climates.
How often must home-stored water containers be rotated?
CDC says water filled into storage containers at home should be replaced every 6 months. Label each container with the fill date.
How can suspicious water be disinfected by boiling or bleach?
Follow local health guidance first. CDC says boiling is best: bring clear water to a rolling boil for 1 minute, or 3 minutes above 6,500 ft. If water is cloudy, first filter it through a clean cloth, paper towel, or coffee filter, or let it settle and draw off the clear water. If boiling is not possible and the bleach label has no drinking-water instructions, CDC lists 8 drops of unscented 5% to 9% household bleach per gallon of clear water, mixed and left for at least 30 minutes. Use 16 drops for water that was cloudy, colored, or very cold. Boiling or bleach cannot make water with fuel, toxic chemicals, or radioactive material safe.
Keep the decision in context
Use our bug out bag checklist for portable water carry, filtration, and evacuation gear. Compare medical supplies and emergency packs in our emergency medical gear index.