Water storage calculator
How much water your household actually needs, how many containers that is, and what it will weigh once it is full.
1. Household
Your numbers
- Total water needed
- 126 gal
- Containers
- 18 × 7 gal
- Drinking & cooking
- 56 gal
- Sanitation
- 56 gal
- Full weight
- 1,051 lb
- Floor space (approx.)
- 4.4 sq ft
Rounding up to whole containers gives you 14 days of supply at this consumption rate.
To disinfect clear water, use 2 drops of unscented 8.25% household bleach per gallon, stir, and wait 30 minutes. Double it for cloudy water, and filter first if you can. Planning guidance only.
Get the water storage worksheet
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Questions people ask
- Is one gallon per person per day really enough?
- One gallon per person per day is the drinking and cooking figure, and it is a floor rather than a comfortable allowance. Sanitation — washing, dishes, flushing — is a separate line in this calculator because treating it as included is how people end up rationing drinking water to stay clean. In hot weather, or if anyone in the household is pregnant, ill or nursing, raise the drinking figure.
- How long does stored water keep?
- Commercially sealed bottled water carries a best-by date but stays safe well beyond it if stored cool and dark. Water you bottle yourself should be rotated every six to twelve months. Store off concrete, out of sunlight, and away from petrol, solvents or pesticides — some plastics let vapours through.
- What about the weight?
- Water weighs 8.34 pounds per gallon, so storage adds up fast. A 55 gallon drum is over 450 pounds when full and cannot be moved once filled. Check that any upper floor or shelf can carry the figure this calculator gives you before you commit to a location.