Hurricane Preparedness Calculator

Fuel, Water & Backup Power for Storm Season

New to this? Plain-English guide

Essential Load (kW) — the power needed to run just the must-haves (fridge, fans, a few lights, phone charging) rather than the whole house.

Usable Battery Capacity (kWh) — the energy you can actually draw from a battery before it should stop discharging — less than the label capacity, since batteries shouldn't be drained to zero.

Generator Runtime (hrs/day) — running the generator only part of the day (e.g. morning and evening blocks) stretches fuel through a long outage.

Days to Prepare For — how long you expect to be without mains power. After major hurricanes, restoration in the Caribbean has taken from days to several weeks.

Household
Backup Power
Battery Backup (optional)
Method: fuel = generator part-load consumption × hours × days + 10% reserve. Water = 5 gal/person/day. Battery hours = usable kWh ÷ essential load.

Results

Generator Fuel Needed
Fuel Containers (5 gal / 20 L)
Estimated Fuel Cost Note
Water Storage Needed
— of which Drinking Water
Battery Runtime per Charge
Daily Generator Energy
Preparedness Checklist
  • Fuel stored in approved containers, away from living areas
  • Water containers cleaned and filled 48h before landfall
  • Generator test-run under load; oil and spare filter on hand
  • Never run a generator indoors or near windows — CO kills
  • Freeze water bottles to hold fridge temperature longer
  • Charge all batteries, power banks, and tools before the storm
  • Cash, medications, documents in waterproof container
  • Trim trees near service drop; secure loose roofing
Related tools: size the generatorsize the water tanksize a battery bank