- How many days to stock and how much water
- How rolling stock works
- Preparing for infants, older people and food allergies
- What goes in a 3-day workplace stockpile
The short answer
The Prime Minister's Office disaster page recommends keeping drinking water and food for at least 3 days, and for a week to prepare for a large-scale disaster. The guideline for drinking water is about 3 litres per person per day.
You do not need to buy a mountain of special emergency rations. With "rolling stock" you buy a little more of what you already eat, eat the oldest items first and replace what you use, so there is always a set amount in the house.
Why 3 days to a week
The Ministry of Agriculture, Forestry and Fisheries (MAFF) food stock guide says it is desirable to keep at least 3 days' to a week's worth of food for everyone in the household. It gives these reasons: restoring electricity, gas and water can take more than a week; relief supplies can take 3 days or more to arrive; and when logistics stop, shops can be short of food for about a week. Depending on your local hazard map, it suggests stocking more, such as two weeks.
Besides food and water, the Prime Minister's Office page lists toilet paper, portable toilets and a portable gas stove. It also recommends securing water for washing and flushing, separate from drinking water, for example by keeping the bath filled.
How rolling stock works
As the guide explains, you buy slightly more of your everyday food, eat whatever has the nearest best-before date first, and buy replacements for what you eat. The cost and effort stay within your normal shopping; you only need a little more storage space.
The guide also suggests choosing by how you eat. Households that cook a lot can keep more dried goods, canned food and pickled plums. Households that rely on ready meals can add retort pouches and freeze-dried food. Households that rarely cook can add things they like, such as cup noodles and snacks.
[Our home stockpile note]
People: __ (water guide: people x 3 litres x days)
Water: __ bottles (kept in: ____)
Staples: __ meals (e.g. microwave rice, dried noodles)
Side dishes: __ meals (e.g. tins, retort pouches)
Heat: portable gas stove, __ canisters
Toilet: portable toilet, __ uses
Next review date: __ / __Infants, older people and food allergies
If someone at home may not be able to eat shelter food, plan their supplies separately. MAFF publishes a dedicated guide for people with special needs; the September 2026 edition is available.
- Infants: powdered or liquid formula, bottles, paper cups, disposable spoons and extra drinking water. Two weeks of baby food is described as reassuring. Make formula with tap water or Japanese mineral water; well water cannot be used.
- Older people: rice porridge, instant miso soup, familiar dried foods and denture cleaner. For people who have trouble chewing or swallowing, add care foods and thickening agents.
- Food allergies: MAFF recommends at least two weeks of supplies for households with special dietary needs. Along with food free of the allergen, prepare a card or bib that shows the allergy, and emergency medicine.
- Chronic conditions: a note of medicine names, doses and prescription details is useful.
Stockpiles at small workplaces
Tokyo's Ordinance on Measures for Stranded Persons asks businesses to make efforts to stock 3 days of drinking water, food and other necessities for their staff (an obligation to make efforts, not a strict duty). The aim is to let staff stay at work rather than all heading home at once after a disaster.
Tokyo's guidance for workplaces suggests planning for the maximum number of people in the office at once, times 3 days: per person, 9 litres of water, 9 meals and portable toilets for 15 uses, plus hygiene items, bedding such as blankets, a radio and chargers. Store supplies in several places and keep a list of locations and best-before dates. One idea it offers is handing out food nearing its date to staff so they get used to eating it. Because needs differ with allergies or health conditions, share what the workplace stocks and ask people to bring what is missing. Workplaces outside Tokyo should check their own local government's guidance.
Checklist
- Is there at least 3 days of water for everyone at home?
- Do you have gas canisters for the stove and portable toilets?
- Have you set aside separate supplies for infants, older people or anyone with allergies?
- Does your workplace have a list of where supplies are and when they expire?
One thing to check today
Count how many days your water and food at home would last for everyone in the household.
How much to stock: home, special needs, work
- At least 3 days
- A week for large-scale disasters
- About 3 litres of water per person per day
→ Rotate everyday food
- At least two weeks of supplies
- Two weeks of baby food is reassuring
- A card showing the allergy
→ Plan their supplies separately
- 9 litres of water per person
- 9 meals per person
- Portable toilets for 15 uses
→ Peak headcount x 3 days