Your water supplies. A clear plan, litre by litre.

Estimate the needs of your home, take stock of your reserve and identify what remains to be prepared.

Your reserve plan

How much water do you miss?

The initial profile provides 4 litres per person per day in total. Adjust the usages according to your situation. The needs of the animals add separately.

01Your home and your goal

Persons, including childrenDuration in days

02The uses to be foreseen

ConsumptionDrink: 2 L/person/day baseline.

L/person/day

Food preparationIndicative distribution, adjustable.

L/person/day

Essential hygieneIndicative distribution, adjustable.

L/person/day

The official benchmark distinguishes 2 L for consumption and 2 L for food and hygiene. The distribution 1 L + 1 L of these last two uses is a PrépaCivile planning choice, not an official prescription.

Animals: total daily needs (L)Add a quantity suitable for your animals. No automatic veterinary coefficient is applied.

03What you already have

Useable water reserve (L)Capacity of containers to be added (L)

Count only water available and suitable for the chosen uses. The result is not a potability check.

04Your margin, if you want onePlanning margin (%)Optional, applied to the total volume calculated. No supplement is imposed.

Local calculations: No input is sent or saved by this tool. No account required.

Understanding · Checking · Acting

How to use your result.

Find the method, useful actions and limitations of the calculation in the same place, on each PrépaCivile tool.

Calculation method

Visible assumptions, a useful result.

The base volume is equal to the number of persons multiplied by the number of days and the sum of the daily uses chosen. The daily needs of the animals are multiplied by the duration, then added. The optional margin is applied to this total.

Example: 4 people × 7 days × 4 L = 112 L. With 40 L already available, 72 L is missing: 8 containers of 10 L are required to cover this shortage.

Practical next steps

Start with a realistic goal.

First, consolidate a 72-hour reserve. The longer objectives of the calculator are personal planning scenarios, with no promise of comfort or guaranteed autonomy.

Limitations of the result

This result estimates a reserve volume. It does not guarantee the potability of water, its conservation, or the coverage of all special needs. Adapt the scenario to local instructions.

Sources and references

Government of Quebec — Contamination or shortage of drinking water : for three days, 6 L per person for consumption and 6 L for food preparation and hygiene, plus animals.
Health Canada—Emergency Safety of Food and Drinking Water 2 L per person per day, with an additional 2 L for food preparation and hygiene.

Sources consulted on November 1, 2026. This profile does not purport to represent the recommendations of all Francophone territories.

Frequently Asked Questions

Why four liters a day?

The profile distinguishes water for the consumption of additional water for food and hygiene. This preparation benchmark does not describe normal domestic consumption.

Should I add the children?

Yes: The basic profile includes each member of the household. It does not apply an automatic discount to children. Special needs, including infants, must be planned with appropriate references.

And in case of heat or special needs?

Needs may increase. Adjust the parameters according to your situation and the instructions of the authorities or professionals concerned. No automatic medical multiplier is applied.

Does the result guarantee that my water is safe?

No. The calculator estimates volumes. It does not validate water quality, treatment, or containers. Use appropriate containers and follow local and manufacturer's instructions.

Are my information kept?

No. This tool calculates on your device, without an account, without input and without local storage. A reload returns the default settings.

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