Sources & method
Every number on your list is quoted from Ready.gov, CDC or the American Red Cross. If they give no number, neither do we.
The rules (R1 to R13)
The code next to each line of your list (R1, R2…) points here. All pages were read on .
- R1
Water per person
1 gallon of water per person per day.
“Water (one gallon per person per day for several days, for drinking and sanitation)”
“Store at least 1 gallon of water per person, per day for 3 days… Try to store a 2-week supply if possible.”
- R2
Hot weather
In very hot weather water needs can double; some people need more.
“Children, nursing mothers and sick people may need more water.”
“In very hot temperatures, water needs can double.”
- R3
How many days
3 days of supplies to evacuate, 2 weeks to stay home.
“Water: one gallon per person, per day (3-day supply for evacuation, 2-week supply for home)”
“Go-Kit: 3 days of supplies that you can carry with you… Stay-at-Home Kit: 2 weeks of supplies. Stores and pharmacies might be closed.”
- R4
Food
Non-perishable food that needs no fridge or cooking, a manual can opener, ready-to-feed formula.
“Store at least a several-day supply of non-perishable food.”
“Be sure to include a manual can opener”
“Use ready-to-feed formula.”
- R5
Medications
Aim for a 1-month supply; at least 7 days in your kit; keep a written list.
“Medications (7-day supply) and medical items”
“Have a 1-month supply of medication in a child-proof container.”
“Talk to your doctor or pharmacist about how you can create an emergency supply of medicines.”
- R6
Pets
2 weeks of food, water and medicine for each animal; a carrier for each pet.
“2-week supply of food for each animal”
“2-week supply of water for each animal”
“2-week supply of any medications”
“1-month supply of flea, tick, and heartworm preventative”
“ideally one for each pet”
“Many public shelters and hotels do not allow pets inside.”
- R7
Light and power
Flashlight, extra batteries, a battery or hand-crank radio, phone chargers and a backup battery.
“Cell phone with chargers and a backup battery”
“Extra batteries in common sizes, such as AA and AAA”
“Hearing aid batteries”
“A generator with at least 20 feet of extension cord(s) rated for outdoor use”
- R8
Power-dependent medical devices
Backup batteries and chargers, a plan with your doctor and power company, more than one facility.
“talk to your doctor or health care provider about what you may be able to do to keep it running during a power outage. You can also ask your power provider to put you on a list for priority power restoration.”
“Purchase an extra battery for a power wheelchair or other battery-operated medical or assistive technology devices.”
“know the location and availability of more than one facility that can help you.”
“Include backup batteries and chargers for your devices (cell phone, CPAP, wheelchair, etc.)”
- R9
Cash and documents
Extra cash and copies of key documents in a waterproof container. No official cash amount.
“Extra cash”
“medication list and pertinent medical information, proof of address, deed/lease to home, passports, birth certificates, insurance policies”
“copies of insurance policies, identification and bank account records… in a waterproof, portable container”
- R10
Infants
Formula, bottles, diapers, wipes and diaper rash cream.
“Infant formula, bottles, diapers, wipes and diaper rash cream”
- R11
Per person
A blanket or sleeping bag and a change of clothes with sturdy shoes for each person.
“Sleeping bag or warm blanket for each person”
“Complete change of clothing… and sturdy shoes”
- R12
Evacuation
Fill the gas tank if evacuation seems likely.
“Keep a full tank of gas if an evacuation seems likely.”
- R13
Food in a power outage
Fridge about 4 hours, full freezer about 48 hours.
“The refrigerator will keep food cold for about four hours. A full freezer will keep the temperature for about 48 hours.”
Supporting quotes
Basic kit items and generator safety lines on your list cite these.
- KIT
Basic kit list
General kit items for a home kit.
“First aid kit · Whistle · N95 or surgical masks · Plastic sheeting · Duct tape · Multi-purpose tool · Map(s) of the area · Sanitation and personal hygiene items”
- GEN
Generator safety
Generators run outdoors only, away from the house.
“Only use generators outside and away from your home and NEVER run a generator inside a home or garage or connect it to your home's electrical system.”
“Carbon monoxide can't be seen or smelled, but it can kill you fast.”
No official number
No agency gives a number for these, so we don't print one:
- How much cash to keep
- How many batteries to buy
- How many flashlights (we suggest 1 per person, labelled as our suggestion)
- How many gallons of water a pet needs (measure your pet's normal daily amount)
- How many diapers a baby uses per day (count your own baby's usual number)
Our suggestionmarks the only number that is ours: 1 flashlight per person, not counting babies.
How we calculate
- People = adults + children + infants.
- Water (gal) = people × days × 1 (R1). Liters = gallons × 3.78541, rounded.
- Bottle cases = gallons × 128 ÷ (24 × 16.9 oz), rounded up.
- Hot weather = water × 2 (R2). Food = people × days person-days (R4).
- Days: 14 when staying home, 3 when evacuating, until you choose (R3).
Storm note history
The calculator is for any hurricane. When a storm is active we add one dated note that points to the National Hurricane Center. We never forecast.
Note added. NHC Advisory 1 (4:00 PM CDT Oct 6, 2026): Tropical Depression Nine (AL092026) over the Gulf, expected to become a tropical storm by early Wednesday and a hurricane on Thursday, and to approach the U.S. northern Gulf Coast on Friday.
NHC advisory text (opens in a new tab)
General preparedness guidance, not medical advice. Not affiliated with FEMA, Ready.gov, CDC, NOAA or the American Red Cross.