About 2 minutes
How much water should I store?
A drinking and cooking baseline, confirmed extra water, container capacity, and filled weight.
Water storageFree household calculators
A little planning.
A clearer next step.
Work out your water supply, check food during an outage, or estimate backup power. Ten practical tools, built around your household.
No account Private Free to use
Start with one question
What would help today?
A useful starting estimate in a few minutes, with the assumptions explained.
About 2 minutes
Is my fridge or freezer food still usable?
A refrigerator/freezer timeline that hands off from elapsed time to temperature evidence.
Outage food safety About 3 minutes
How long will my battery last?
Runtime from constant watts or measured 24-hour energy, with a separate running-output check.
Battery runtimeBrowse by job
Find the right tool for the job
Find a specialist tool by job.
Start a household plan
Size supplies
Plan backup power
Compare approaches
Make a portable plan
What stays on this device
Calculator drafts and saved My Plan data stay in this browser until you clear them. Result links are created only when you choose to share; they include only the normalized calculator settings allowed by that tool's share policy and never reuse a saved draft.
Prepare before estimating
Record and verify
Turn a starting estimate into a usable plan.
Calculator: create a starting estimate.
Worksheet: verify, record, locate, and practice it.
My Plan: keep concise results and next steps on this device.
- Household Water Plan Worksheet Record containers, storage locations, treatment, and refill checks after a water estimate.
- Essential-Load Backup Power Worksheet Verify the devices, watts, locations, and power priorities that matter during an outage.
- Long-Outage Decision Log Keep a written record of changing conditions, checks, and next decisions.
Public-interest sharing & citation
Link these calculators in CERT, HOA, utility, or neighborhood preparedness packets
Community Emergency Response Teams (CERT), neighborhood associations, campus safety offices, and local reporters may link directly to any calculator or printable worksheet at no cost and with no account wall. Each tool runs locally in the reader's browser and cites CDC, FEMA, USDA FSIS, or CPSC primary standards.