Free Tool
Water Storage Calculator
Water is the single most critical item to have stored before a disaster. This calculator gives your household a real target number to start from — not a generic rule of thumb.
Water Storage Calculator
Enter your household details to see exactly how much water you need to store.
Include everyone in your household
Each pet needs about 1 quart per day
FEMA recommends 72 hours minimum; 2 weeks is better
Your Water Goal
6
gallons (22.7 liters)
Your real number can run higher — climate, activity level, and medical needs all push water needs up. Use this as your floor.
2
gallons/day
(7.6 L)
2
standard 5-gal
containers needed
Storage options
Based on FEMA's 1 gallon/person/day minimum. Adjust for climate, medical needs, and pets. Two weeks of storage is strongly recommended.
Water storage: what most people get wrong
Store-bought vs. tap water
Both are fine. Municipal tap water stored in food-grade containers (marked HDPE #2 or PETE #1) keeps for up to 6 months if sealed tightly. Replace every 6 months.
Don't forget non-drinking uses
Flushing, hand-washing, and basic hygiene add up fast. The 1-gallon figure covers drinking and basic sanitation. Consider storing more if you have a baby at home.
Bathtub as a backup
A WaterBOB bathtub liner lets you store 100 gallons from your tap before a storm hits. Buy one now — it stores flat and it's inexpensive. Fill it when alerts are issued.
Never store near chemicals
Avoid storing water containers in garages where lawn chemicals, gasoline, or pesticides are kept. Even sealed containers can absorb odors from strong chemicals nearby.