Form PL-1 · Method
How the readiness score works
Every answer becomes days covered. The headline is the weakest critical system, because a home runs out when its first essential runs out.
By PowerLockdown Editorial · Updated October 31, 2026
The rule
- Each system converts to days covered, using the low end of the range you picked.
- The critical systems are water and food, plus heat where winters are cold and medicine where someone needs it.
- The score is the fewest days among the critical systems, rounded down to whole days and capped at 90+.
- Support systems (backup power, light, radio, sanitation, cash) are charted and drive the next actions, but do not set the score.
- Shared links round down to a band: 0, 1, 2, 3, 5, 7, 10, 14, 21, 30, 45, 60, 90+ days. A 9-day score shares as 7.
Worked example
Four people with 30 gallons of water: 30 ÷ (1 × 4) = 7.5 days of water. With two weeks of food and cold winters covered by a wood stove with a month of wood, water is the weakest critical system. The score is 7 days, and the first action is to store about 10 more gallons to reach 10 days.
What it leaves out
The score does not know your local hazards, your building, or your neighbors. A household that shares water and heat with the people next door can last longer than its own numbers say. Use it to find the first gap, then close it.
Every assumption
| System | Days rule | Basis | Counts toward score |
|---|---|---|---|
| Water | Gallons stored ÷ (1 gal × people) | CDC and Ready.gov: at least 1 gallon per person per day, for drinking and hygiene. | Always |
| Food | Days of food that needs no refrigeration | Ready.gov: keep non-perishable food that needs little or no cooking. | Always |
| Heat | Days of fuel for heat that works without the grid | Season-weighted: not counted where winters are mild. In severe winters, blankets alone count as 0 days. | Cold and severe winters |
| Medical | Days of daily medicine on hand, limited by refrigeration and power | FDA: insulin may stay unrefrigerated at 59 to 86°F for up to 28 days. A plug-in device lasts as long as backup power. | When someone needs it |
| Backup power | Banks 1 day, power station 2, generator 3 or 14 (by fuel), station with solar 30 | Our planning assumption. Solar keeps recharging; fuel and batteries run out. | Only when a medical device depends on it |
| Light | Candles 0, flashlights 3, lanterns with spare batteries 7, solar-rechargeable 30 | Ready.gov recommends flashlights over candles. Day values are our planning assumption. | Support |
| Radio and news | Phone only 1, battery radio 7, crank or solar NOAA radio 90 | Ready.gov's basic kit includes a battery-powered or hand-crank radio with NOAA Weather Radio alerts. | Support |
| Sanitation | Nothing 0, basic 3, bucket toilet kit 14, a month of supplies 30 | Ready.gov's kit lists moist towelettes, garbage bags and plastic ties. | Support |
| Cash | Days of essentials you can pay for in cash | Card readers and ATMs need power. Day values are your own estimate. | Support |
Sources
- CDC: Creating and Storing an Emergency Water Supply
- Ready.gov: Water
- Ready.gov: Food
- Ready.gov: Build a Kit (updated 07/01/2026)
- Ready.gov: Power Outages (updated 06/04/2026)
- FDA: Insulin Storage and Switching Between Products in an Emergency
- FDA: Tips About Medical Devices and Natural Disasters
- CDC: Carbon Monoxide Poisoning Basics
- CPSC: Carbon Monoxide Information Center