72-hour kit vs 2-week supply: which do you need?

By SGWNI. Checked on 2 November 2026.

You need both, because they do different jobs. A 72-hour kit is what you take with you if you have to leave home. A 2-week supply is what you live on if you stay. The CDC puts it that way: plan for at least a two-week supply of food at home, or a three-day supply on hand if you plan to evacuate. The American Red Cross gives the same split for water and food. If you can only do one right now, start with 3 days, because it’s the first step toward both.

The difference at a glance

The water figures use the CDC and Ready.gov amount of at least 1 gallon per person per day.

What the official sources say

The sources differ more in wording than you’d expect, and it’s worth knowing who says what.

• CDC, for hurricanes and floods: at least 2 weeks of food at home, or 3 days if you plan to evacuate.
• CDC, for water: at least 3 days, and a 2-week supply if possible.
• American Red Cross: a 3-day supply for evacuation and a 2-week supply for home, for both food and water.
• Ready.gov: “several days” of food and water. It doesn’t give a fixed number on its current pages.

None of these is a promise that help arrives on day 4 or day 15. They’re planning figures. Where you live and what’s likely there should shape how far you go.

When 3 days is the right answer

A 72-hour kit makes sense for anyone who might be told to leave: a hurricane evacuation zone, wildfire country, a flood plain, or a building you might have to leave at short notice.

The idea is that it’s ready before you need it. The CDC’s advice if you’re ordered to evacuate is to grab your kit and take only what you really need, like your phone, chargers, medicines, ID and cash.

Weight is the catch. A gallon of water weighs about 8.3 pounds, so 3 gallons for one person is about 25 pounds. That’s fine in a car trunk and hard work on your back. If you’d leave by car, keep the water in jugs by the door or in the car. If you might be on foot, you’ll have to carry less, and that’s a real trade-off to think about ahead of time, not during the emergency.

Keep the food ready to eat and light. Think bars, peanut butter, dried fruit, and a few small cans with pull tabs. Our go bag checklist builds a list for your household, with reasons for each item.

When 2 weeks is the right answer

Often you won’t need to go anywhere. The power goes out, a road closes, or stores can’t restock for a while, and you stay put. Ready.gov notes that after a hurricane you may not have access to supplies for days or even weeks.

A 2-week supply can’t be in a bag, and it doesn’t need to be. It’s mostly a fuller pantry. The CDC says it’s not necessary to buy dehydrated or other types of emergency food, and suggests foods with a long storage life that need little or no cooking, water or refrigeration, in case utilities are disrupted.

The hard part of 2 weeks is water. At 1 gallon a day, one person needs 14 gallons, and a family of four needs 56. A set of stackable containers you fill yourself is one way to do that, as long as you use food-grade containers and replace the water every 6 months. Our water storage calculator works out the containers for your household.

Food takes more thought but less space. The food storage calculator turns your household and timeline into a shopping list.

How they fit together

You don’t need two separate systems. Treat them as layers.

1. Get to 3 days at home first. Count what you already have. This covers most short outages, and you’ve started.
2. Pack the kit. Move or duplicate 3 days of ready-to-eat food, water, medicine, documents, a flashlight and chargers into one grab-and-go place.
3. Grow the pantry. Add to your normal groceries, one item per trip, until you reach 2 weeks.
4. Add a smaller kit for elsewhere. Ready.gov suggests being ready to shelter at work for at least 24 hours, and keeping supplies in the car in case you’re stranded.

Medicine is the part that doesn’t fit neatly. The Red Cross lists a 7-day supply, and other sources range from 3 days to a month. Ask your pharmacist or doctor what’s possible for your prescriptions.

Keeping both up to date

The kit is the one most likely to go stale, because you don’t touch it. Food in a bag sits through summer heat if it’s in a car, and the USDA says heat shortens the life of canned goods. Check it at least once a year, as Ready.gov suggests, and swap the food into your kitchen before it gets old.

The pantry looks after itself if you use the oldest food first. Count what you have every so often, because numbers drift as you cook. That’s what the Prep app does: it tracks your stock by item and works out how many days you’d last as you use things.