Quick answer: A 30-day emergency supply for one person is about 30 gallons of water (or a smaller stored supply plus a filter that can treat more), about 60,000 calories of shelf-stable food, a way to cook it, light and power for a month, a 30-day supply of any prescription medicine, a full first aid kit and basic sanitation. Build it in four weekly steps so you are covered for 72 hours by the end of week one, and for a month by the end of week four.
Late October 2026 changed the conversation. The UK launched its three-year Be Ready campaign asking every household to prepare for three days without power, water or phones. The Pentagon's FORTRESS plan asks major US bases to run 90 days on their own power, water and fuel. A widely shared call from a former FBI deputy director told Americans to keep 30 days of food, water and power at home. Experts quickly pointed out there is no specific threat behind any of this, and they are right. But a month of supplies is a sensible target for any household, whatever the reason: a long power outage, a hurricane, a winter storm, a job loss or a supply-chain shock.
This guide turns that goal into a plan you can finish in four weekends. Every number below is per person, so multiply by the people (and pets) in your home.
In this guide
- Why 30 Days, and Why Now
- The 30-Day Math for One Person
- Week 1: Water and the First 72 Hours
- Week 2: Food That Stores for Years
- Week 3: Power, Light and Communication
- Week 4: Health, Sanitation and Security
- Three Budgets: $250, $1,100 and $3,000
- Storing and Rotating Your Supply
Why 30 Days, and Why Now
Most official guidance stops at 72 hours. Ready.gov asks for supplies to last several days, the European Commission recommends at least 72 hours of self-sufficiency, and the UK's Be Ready campaign asks for three days. Some countries go further: Sweden asks households to manage for at least a week, and Germany recommends up to 10 days.
Seventy-two hours is the time it takes for help to arrive after a typical disaster. Thirty days covers what 72 hours does not: a grid failure that lasts weeks, stores that stay empty after a regional event, or a household budget emergency. It also means you are not the one competing for the last case of water when everyone else rushes the store.
Start with 72 hours, then build. If you only do one thing this week, finish our 72-hour emergency kit checklist. Everything in this guide stacks on top of it.
The 30-Day Math for One Person
These are the planning numbers we use. They match US government guidance where it exists and err on the generous side where it does not.
| Category | Per person, per day | Per person, 30 days | Notes |
| Drinking and hygiene water | 1 gallon | 30 gallons | FEMA and the CDC minimum; more for hot climates, nursing mothers, children and the sick |
| Food energy | 2,000 calories | 60,000 calories | Active adults may need more; small children less |
| Cooking water for freeze-dried food | about 3–4 cups | about 6–8 gallons | From the food labels: e.g. 100 cups for a 14-day bucket |
| Prescription medicine | Your normal dose | 30 days plus a buffer | Ask your doctor or pharmacist about an early refill |
| Light | 4–6 hours | 120–180 hours | Rechargeable LED lights with a way to recharge them |
| Phone charging | 1 charge | 30 charges | About 15 Wh a charge for most phones |
Water is the heaviest and bulkiest item: 30 gallons weighs about 250 pounds. Most homes cannot store a full month of water for everyone, which is why a filter matters. A good filter turns rain barrels, creeks, pools and stored water that has gone stale into drinking water, so you can store less and still be covered.
Week 1: Water and the First 72 Hours
Week one is about the first 72 hours, and water comes first.
Store three days of water now
- 3 gallons per person, in sealed commercial bottles or food-grade containers. The CDC advises replacing home-filled water every six months.
- Containers we carry: the Coghlans Collapsible Water Container 5 Gallon and the Coghlans Expandable Camp Jug. For larger amounts, see our guide to 55-gallon barrels vs stackable tanks.
- Treat long-term stored water with Aquamira Chlorine Dioxide Water Treatment, which treats up to 60 gallons and gives sealed stored water a five-year shelf life according to the maker.
Then add a filter that can cover the rest of the month
For 30 days you want a filter that can treat far more water than you can store. Here is how our most popular home options compare, using the specifications on each product page:
| Filter | Type | Rated life | Removes viruses? | Best for |
| LifeStraw Escape | Pressurized 20 L tank | 18,000 L membrane | Yes (99.99%) | Families; 1+ liter a minute, no gravity needed |
| LifeStraw Peak Gravity Purifier 8L | Gravity bag | 18,000 L | Yes | Households; about 30 L an hour hands-free |
| LifeStraw Peak 8L Gravity Filter System | Gravity bag + clean storage bag | 2,000 L | No (bacteria and parasites) | Clear tap or well water |
| Sawyer One Gallon Gravity System | Gravity bag | Up to 100,000 gallons | No | Budget household backup |
| Sawyer Squeeze | Squeeze / inline | Lifetime warranty | No | Go bags and backup |
| Grayl GeoPress Purifier | Press bottle | 250 L per cartridge | Yes (99.99%) | Personal purifier; also reduces chemicals |
Filter or purifier? A filter removes bacteria and parasites. A purifier also removes viruses, which matters with flood water, untreated surface water near people, or anywhere sewage may be in play. If you can afford only one, choose a purifier. Our water storage guide goes deeper on choosing.
Week 2: Food That Stores for Years
Freeze-dried and dehydrated meals are the backbone of a 30-day supply because they last up to 25 years, need no refrigeration and only need hot water. The Ready.gov food guidance favors foods that need no refrigeration, little cooking and little water; long-shelf-life pouches fit that brief, especially when paired with some canned food you already eat.
Here is the cheapest way we have found to reach 60,000 calories with the ReadyWise range, based on the calorie totals on each product page:
| Option | Calories | Days at 2,000 kcal | Price |
| 2 × ReadyWise 14 Day Emergency Food Bucket + 1 × ReadyWise 7-Day Grab Bag | 65,080 | 32 | $382.97 |
| 1 × ReadyWise 240-Serving Package + 1 × ReadyWise 72 Hour Emergency Food Supply | 59,660 | 30 | $622.98 |
| 1 × 120 Serving Breakfast Bucket + 1 × 84 Serving Breakfast & Entree Bucket + 1 × 52 Serving Prepper Pack | 56,020 | 28 | $573.97 |
Prices are current store prices as of November 5, 2026. Our emergency food bucket comparison breaks down every ReadyWise bucket by cost per day, servings and water needed.
Do not forget
- A way to heat water that works without power. Every freeze-dried meal above needs boiling water.
- Cooking water. The 14-day bucket alone needs about 100 cups. Count it in your water plan.
- Foods you already eat. Canned beans, rice, oats, peanut butter and coffee rotate through your pantry and make a month far more bearable.
- Special diets. The 84 Serving Gluten Free Bucket and the 90 Serving Organic Bucket cover two common needs.
Week 3: Power, Light and Communication
A month without grid power is where most plans fall apart. Plan for three layers:
- Light. A headlamp for each person and one area light per room you will live in. The Dark Energy Oracle headlamp runs up to 50 hours on a charge; the Dark Energy Sentinel area light lights a room for up to 20 hours.
- Phone and radio power. A rugged power bank such as the Dark Energy Poseidon XL (27,000 mAh, 100 W USB-C) plus a folding solar panel like the Spectre 18W keeps phones and radios alive indefinitely in daylight.
- Appliance power. A portable power station runs a fridge, CPAP or medical device for hours or days. The EcoFlow RIVER 2 Max (499 Wh) covers small loads; the EcoFlow DELTA 3 Max Plus (2,048 Wh, 3,000 W) runs a full-size fridge; whole-home systems like the EcoFlow TITAN 5000 cover the house. Our grid outage guide shows how to size one.
For news when the internet is down, a battery radio such as the ETON Elite Traveler receives AM, FM, longwave and shortwave. See our radio guide for two-way options.
Week 4: Health, Sanitation and Security
- First aid. A full kit, not a box of bandages: the My Medic MyFAK or the North American Rescue RED Kit, which adds a C-A-T tourniquet for severe bleeding.
- Medicine. 30 days of prescriptions, plus pain relievers, antihistamines, electrolytes and anything your family uses regularly. Read our note on the critical item missing from most kits.
- Sanitation. Heavy trash bags, a bucket toilet, bleach, hand sanitizer, wipes and toilet paper. If water pressure fails, sanitation becomes the biggest health risk.
- Documents and cash. Copies of IDs, insurance and prescriptions, and small bills. Card readers and ATMs need power and networks.
- Signal protection. A SLNT Waterproof Faraday Dry Bag protects a spare phone, radio and documents from water, and blocks wireless signals.
Three Budgets: $250, $1,100 and $3,000
| Budget | What it covers | Example from our range |
| About $250 | 72 hours of food and water treatment, light, first aid basics | 72 Hour Food Supply, Sawyer Squeeze, Aquamira drops, Oracle headlamp, MyFAK Sidekick |
| About $1,100 | 30 days of food, a purifier, light and phone power | 2 × 14 Day Bucket + 7-Day Bag, Peak Gravity Purifier, Poseidon XL, Sentinel light, MyFAK |
| About $3,000 | 30 days for two, household purifier, appliance power | 240-Serving Package × 2, LifeStraw Escape, DELTA 3 Max Plus, lights and first aid |
Prefer a single box? Our ready-made kits include the Uncharted SEVENTY2 72-hour system, which packs 24 items into a waterproof 32 L pack.
Storing and Rotating Your Supply
- Keep food in a cool, dry, dark place. Heat is the enemy of shelf life.
- Write the purchase date on every container and keep a simple rotation log.
- Eat and replace canned food on a schedule; long-shelf-life pouches can sit.
- Replace home-filled water every six months, and check filters and batteries twice a year when the clocks change.
- Keep a printed copy of this plan with the supply.
Common Questions
How much food do I need for 30 days?
Plan on about 2,000 calories a person a day, or 60,000 calories for 30 days. Count calories, not servings: a "serving" on long-term food labels is often 150–300 calories.
How much water do I need for 30 days?
The FEMA and CDC minimum is one gallon a person a day, so 30 gallons for one person. Most people store part of that and cover the rest with a filter or purifier that can treat rain, well, creek or stored water.
What should I buy first?
Water and a way to treat it, then 72 hours of food, then light and first aid. After that, grow food to 30 days and add power.
How long does freeze-dried emergency food last?
ReadyWise lists up to a 25-year shelf life for its buckets when stored in cool, dry conditions.
Is a 30-day supply overkill?
No. Officials recommend 72 hours as a minimum, and several countries recommend a week or more. A month covers long outages and gives you room to help neighbors.
Can I build this on a budget?
Yes. Start with the $250 tier and add a bucket a month. Two 14-day buckets and a 7-day bag reach about 32 days of food for under $400.
Sources
- Ready.gov: Build a Kit
- Ready.gov: Water
- Ready.gov: Food
- CDC: Creating and Storing an Emergency Water Supply
- European Commission: EU Preparedness Union Strategy (March 26, 2025)
- UK Government: Be Ready campaign
- Swedish Civil Defence and Resilience Agency: In case of crisis or war
- Germany BBK: Personal preparedness
- NewsNation: Pentagon FORTRESS plan hardens US bases for 90 days
