Reader planning tools

Check the quantities before you buy

Work through one real task at a time. These calculators perform transparent planning arithmetic; they do not certify a system, prescribe water rationing, or establish a medical support plan.

Calculations run on this page. No account, email, analytics, or server submission is used. Values are not saved when you leave or reload. Use Print to keep a local copy and avoid including sensitive medical or identity information.

Stored-water planning

Start with a counted reserve and a safe way to handle it. The one-gallon default follows CDC emergency storage guidance; increase the plan for the actual household, heat, illness, pregnancy, animals, and other needs.

The baseline is not a maximum or an individual drinking prescription.
Add measured requirements not covered above, including pets and separate tasks.
Choose a size each operator can handle. Filled weight excludes the container.
Method, source, and practical checks

Total = people × days × daily allowance + additional water. Gap = total minus the safe stored quantity, with a minimum of zero. New containers = gap divided by fill size, rounded up. Liters use 3.785411784 per US gallon; water weight uses approximately 8.34 pounds per gallon.

CDC recommends at least one gallon per person per day for three days and trying for two weeks where possible. This tool permits a household-selected planning period without promising that a particular duration is adequate. Food-grade containers, clean dispensing, storage locations, and replenishment still require planning. Never treat a weight result as proof of shelf, floor, or balcony capacity.

CDC: How to Create an Emergency Water Supply, consulted November 7, 2026.

Essential-energy estimate

Use measured daily energy for the appliances you intend to supply. If starting from steady loads, add watts × hours for each item. A device that cycles or changes load should be measured over a representative period.

Example arithmetic only; replace it with your measurements.
Combined usable capacity and conversion/standby losses. Use the actual equipment evidence.
Method and limits

Required delivered energy = daily watt-hours × days. Illustrative nameplate energy = required delivered energy ÷ delivered fraction. No recharge, solar generation, temperature effect, or battery aging is assumed beyond the fraction you enter. These results do not check continuous watts, surge watts, connector compatibility, charge limits, cable or fuse sizes, or installation requirements. Verify those independently with the manufacturer and a qualified installer when required. Never backfeed a wall outlet.

Life-support equipment and temperature-sensitive medicine require a plan agreed with the care team, including relocation when needed. This calculator is not a substitute for it.

US Department of Energy: Measuring Standby Power explains using measured energy over time when power varies. Consulted November 7, 2026.

Meal-component quantities

Count one component of a familiar menu, such as a shelf-stable main dish. Repeat for each component. This count does not establish calorie adequacy, balanced nutrition, allergy suitability, food safety, or shelf life.

Check the actual label and the portion your household uses.
Measured preparation water only, not drinking or cleanup water.
Method and practical checks

Target portions = people × days × portions per person per day. New packages = the positive portion gap ÷ portions per package, rounded up. Preparation water = new packages × cooking water per package. Review a complete menu, fuel, permitted cooking location, cleaning water, dietary needs, and safe handling of opened food. Keep dates visible and use the oldest suitable stock first. Do not invent a storage life from these results.