Something has a date on it
What to buy if you have three days to prepare
A storm is forecast. An outage is announced. A strike, a shortage, or a disruption is expected by the weekend. You have about three days and some money. Here is what matters first, second, and third.
The sequence is the same whatever the reason. Irreplaceable things first, while the stores are calm. Food and consumables second. Systems and the gaps the inventory revealed third. Then stop, and organize.
Before you read further
What this guide assumes
There is a credible reason and a short clock. Not a rumor: a forecast, a utility notice, an announced action, or a confirmed disruption that will reach your area within days. If you are not sure the reason is credible, start here instead and come back if it checks out.
It also assumes stores are open now, you can get to them, and you would like your household to manage for at least a week or two afterward. Adjust the quantities to the duration you actually want; the stock-up guide explains how to choose one.
If the disruption is a named hazard, pair this page with its plan. The local risks section has a before, during, and after checklist for each one, and the Help gateway has the plan for when it arrives.
Day one
Inventory, and the things that cannot be substituted
Day one is the day everyone else has not started yet. Spend it on the items with no substitute and on counting what you already own, so that days two and three are short trips rather than long ones.
Refill prescriptions and gather medical needs
Call the pharmacy first thing. Ready.gov notes that an emergency can make it hard to refill a prescription or find an open pharmacy, and pharmacy lines lengthen fast once a forecast is public. Refill on the earliest day your plan permits and ask about a 90-day supply. Add medical supplies, hearing-aid batteries, spare glasses or contact supplies, and anything a household member depends on daily. Prescription preparedness covers early-refill rules and refrigerated medications.
Infant, pet, and special-diet supplies
Formula, diapers, wipes. Pet food, litter, and pet medications. Foods for anyone with an allergy or a medical diet. These are the items that empty first and cannot be improvised, so they come before the general groceries.
Fill the vehicle and get cash
Fuel pumps and card readers both run on electricity. Fill every vehicle. Withdraw a small amount of cash in small bills, which Ready.gov recommends because ATMs and credit cards may not work during a disaster. A few days of groceries and fuel, not the savings account.
Count food, water, and light
Twenty minutes with a notepad. Food in days, allowing for what is in the fridge and freezer to be eaten first. Water in gallons against CDC's one gallon per person per day. Flashlights tested, batteries counted, power banks charged. The gaps you write down tonight are the entire shopping list for days two and three.
Check documents and banking access
Know where the insurance policies, identification, and account information are, and make copies if none exist. Ready.gov recommends copies of important documents in your supplies. Write down the phone numbers you would need without a phone: family, doctor, pharmacy, utility, insurer.
Day two
Food, water, and the consumables
The grocery day. Shop from the gap list, not from the shelf display, and shop early in the day. Buy what your household already eats, deeper. Nothing on this list is specialty food.
Water to the number
CDC's floor is one gallon per person per day for three days, with a two-week supply if you can manage it, and more for pregnant women, people who are sick, pets, and hot climates. Four people for a week is 28 gallons. Commercially bottled water in its sealed container is the simplest form. If you have food-grade containers, you can fill them from the tap on day three while the water is still running; Ready.gov advises replacing water you bottled yourself every six months.
Ordinary food, with a no-cook share
Ready.gov's guidance: choose foods your family will eat, favor canned foods, dry mixes, and staples that need no refrigeration, cooking, water, or special preparation, and include a manual can opener. Rice, pasta, oats, canned beans and vegetables, canned fish and chicken, peanut butter, crackers, shelf-stable milk, cereal, dried fruit, nuts, oil, salt, coffee. Comfort food counts.
Make sure several days of it can be eaten cold. If the power goes, FDA's figures are about four hours for a closed refrigerator and 48 hours for a full freezer, 24 if half full, so the first days come from the fridge and freezer anyway.
Hygiene and household consumables
Toilet paper, soap, hand sanitizer, toothpaste, feminine hygiene products, diapers, trash bags, paper towels, detergent, and the over-the-counter medicines your household uses. Ready.gov's list names pain relievers, anti-diarrhea medication, antacids, and laxatives. Buy to the same duration as the food.
Do the laundry, the dishes, and the trash tonight
Start the disruption with clean clothes, clean dishes, empty bins, and a clean kitchen. It costs nothing and buys several easy days. Charge everything overnight.
Day three
Systems, and whatever the inventory said was missing
The last shopping day covers the systems that make the food and water usable: light, power, a radio, a safe way to cook, first aid, and the odd items the inventory turned up. Finish early. Late errands in worsening conditions are how households turn a prepared evening into an emergency.
Light and batteries
A flashlight or headlamp per person and the batteries they take, plus a lantern for a shared room. Buy batteries for what you own before buying new lights. Emergency lighting covers what lasts.
Phone power and a radio
A power bank that can recharge each phone at least once, cables, and a car charger. A battery or hand-crank radio; Ready.gov's kit lists a battery-powered or hand-crank radio and a NOAA Weather Radio with tone alert. NOAA Weather Radio carries warnings for all hazards, not only weather. If you cannot find one, the car radio works.
Water containers, and fill them while the tap runs
Food-grade containers for any gap the bottled water did not close. Fill them, pots, and pitchers before the disruption begins, while the water is clean and pressurized. If a boil-water notice follows, CDC's instruction is a rolling boil for one minute, three minutes above 6,500 feet. Water storage containers covers what to buy and what to avoid.
A safe cooking plan, or a no-cook plan
If you have an outdoor grill or camp stove and a safe place to use it, make sure you have fuel, matches, and a manual can opener. If you do not have a safe outdoor place, plan to eat without cooking. Do not buy a device to use indoors.
CDC's rules: never burn charcoal indoors, never use a portable gas camp stove indoors, and never run a generator inside a home or garage, even with doors and windows open, or closer than 20 feet to any window, door, or vent. Cooking during an outage is written for households without a yard.
First aid and the small parts
Top up the first aid kit. Then the cheap items whose absence is disproportionately annoying: batteries for smoke and carbon monoxide alarms, a spare furnace or water filter, tape, a basic tool set, a can opener if the inventory did not find one. The first aid kit checklist is the shopping list.
Whatever day one's list still shows open
Check the inventory against what you have bought. Close the real gaps. Do not add anything that was not on the list; a new idea on day three is almost always the store's idea rather than yours.
The evening of day three
Stop shopping and organize
This is when a pile of groceries becomes preparedness. Group food by type and put dates where you can see them. Plan the first few days of meals from the fridge and freezer, then from the shelf. Put the flashlights where hands will find them in the dark. Tell everyone in the household where the water, the radio, the first aid kit, and the cash are. Charge every device one last time.
Then sit down. You are as ready as three days allow, and better placed than most households in your area. If the disruption arrives, the Help gateway has the plan for the day itself. If it passes you by, you have a deeper pantry, a full tank, and a household that knows where things are.
Five things not to do in three days
- 01Do not empty the bank account. A small amount of cash is the goal. Rent and the bills that follow the disruption still need paying.
- 02Do not buy a generator without a safe outdoor place to run it and a load you have actually calculated. A generator bought in a hurry is the one most likely to end up in a garage.
- 03Do not bring gasoline, propane cylinders, or charcoal into living space. Fuel storage is a decision for a calm day, covered in the Energy section.
- 04Do not buy food nobody in the house has eaten before. Three days is not the time to find out.
- 05Do not run one more errand after conditions start to turn. Whatever it was, it was less important than being home.
Pair this page with
The plan for the disruption itself
Three days of shopping covers supplies. The pages below cover what to do when the event arrives.
Your local risks
Before, during, and after checklists for each hazard.
Power outage action plan
The first hours and days when the lights go out.
Water outage action plan
When the tap stops or a boil-water notice arrives.
First 72 Hours
The baseline this page is building toward.
Preparedness in an apartment
The same three days, bounded by space and a building you do not control.
I think I need to stock up
The full version: inventory, duration, buying order, stop point.
Last reviewed: September 26, 2026. Water quantities and boil-water guidance cite CDC; food, medication, radio, document, and cash guidance cite Ready.gov; refrigerator and freezer times cite FDA; generator, charcoal, and camp stove placement cite CDC. This page is not medical or financial advice.