How Much Water to Store for Emergencies
How Much Water to Store for Emergencies: Calculations and Assumptions
Knowing how much water to store for emergencies keeps your household safe during a disruption. This guide explains the one-gallon rule, the factors that change it, and how to calculate your household's needs.
Quick Answer
Store at least one gallon of water per person per day for at least three days. That covers drinking and basic sanitation. For a family of four for three days, that is 12 gallons. Adjust for pets, medical needs, hot climates, and longer disruptions. The one-gallon rule is a starting point, not a ceiling.
Key Takeaways
- •One gallon per person per day is the minimum.
- •Adjust for pets, medical needs, and hot climates.
- •Start with three days, then expand to two weeks.
- •Store extra if you rely on freeze-dried food, which needs water.
The One-Gallon Rule
Emergency agencies recommend at least one gallon of water per person per day. That covers about half a gallon for drinking and half a gallon for sanitation. It is a minimum, designed to keep you alive and clean for a short disruption.
The rule assumes moderate temperatures and normal activity. In hot weather, during physical labor, or for pregnant or nursing people, you need more. The one-gallon rule is a starting point; adjust it to your household.
Factors That Change Your Needs
Increase your supply for:
- •Hot climates, where you need more water to stay hydrated.
- •Pets: about 1 ounce per pound of body weight per day for dogs and cats.
- •Medical needs and conditions that require more water.
- •Pregnant or nursing household members.
- •Freeze-dried or dehydrated food, which needs water to prepare.
- •Longer disruptions, beyond three days.
Calculating Your Household's Needs
Start with the one-gallon rule and adjust. For a family of four in a moderate climate for three days: 4 people x 1 gallon x 3 days = 12 gallons. For two weeks: 4 x 1 x 14 = 56 gallons.
Add for pets and special needs. A 50-pound dog needs about 50 ounces, or 0.4 gallons, per day. For two weeks, that is about 5.6 gallons. Add it to your total. Round up to be safe.
Storing and Rotating Your Supply
Store water in food-grade containers in a cool, dark place. Rotate every six months. If you store a large supply, consider a mix of small containers for easy use and larger containers for bulk storage.
A filter can supplement stored water but does not replace it, and does not make chemically contaminated water safe. Store enough to cover your needs without relying on a filter, then keep a filter as a backup.
Water Needs Calculator
| Household | 3 days | 14 days |
|---|---|---|
| 1 person | 3 gallons | 14 gallons |
| 2 people | 6 gallons | 28 gallons |
| 4 people | 12 gallons | 56 gallons |
| 4 people + 50 lb dog | 13.2 gallons | 61.6 gallons |
| 4 people, hot climate | 24 gallons | 112 gallons |
Frequently Asked Questions
How much water should I store per person?
At least one gallon per person per day. That covers drinking and basic sanitation. Adjust up for hot climates, pets, medical needs, and freeze-dried food.
How much water does my pet need?
About 1 ounce per pound of body weight per day for dogs and cats. A 50-pound dog needs about 50 ounces, or 0.4 gallons, per day. Add this to your household total.
Is one gallon per day enough in hot weather?
It is a minimum. In hot weather, during physical labor, or for pregnant or nursing people, you need more. Double the supply in hot climates to be safe.
Do I need to store water if I have a filter?
Yes. A filter supplements stored water but does not replace it, and does not make chemically contaminated water safe. Store enough to cover your needs, then keep a filter as a backup.