How Much Water Do I Need for 2 Weeks? (Calculator Inside)

Two weeks is the longer target in official US guidance. CDC asks for at least 3 days of water and says to try for a 2-week supply if you can. The calculator above does the arithmetic for your household. Below I explain where the numbers come from, how to store that much water in an ordinary home, and what to do if two weeks feels out of reach.

The figure to plan around

Source	Per person per day
CDC (US)	At least 1 gallon (3.8 L)
Canada.ca emergency kits	About 4 L (about 1 gallon)
PreparedBC	4 L, for drinking and sanitation
Health Canada	2 L to drink, plus 2 L for cooking and cleaning

The US and Canadian figures land in the same place: roughly one gallon, or four litres, per person per day. That is what the calculator uses. It covers drinking and basic hygiene, not showers or laundry.

The two-week totals

For a 14-day supply:

Household	US gallons (CDC)	Litres (Canada.ca)
1 person	14 gal (53 L)	56 L (14.8 gal)
2 people	28 gal (106 L)	112 L (29.6 gal)
4 people	56 gal (212 L)	224 L (59.2 gal)

The Canadian column is a little higher because 4 L is slightly more than a US gallon. Either is a sound target.

Who needs more

CDC suggests storing more than the basic amount for pregnant women, people who are sick, pets and hot climates. PreparedBC says hot temperatures can double water needs. Tick the hot weather box in the calculator to see what doubling looks like. If you live somewhere with hot summers, it is worth planning around the doubled number for that season.

Pets. Canada.ca gives averages of about 4 L (about 1 gallon) a day for a dog and 1 L (about 1 quart) a day for a cat. PreparedBC gives a weight-based rule of about 30 mL per kg of body weight per day, so a large dog may need more than the average. I wrote a whole post on prepping with pets.

Storing two weeks of water at home

Water is heavy. A litre weighs about 1 kg, and a US gallon about 8.3 lb. Two weeks for two people is over 200 lb (about 100 kg). A few practical points from CDC:

• Use food-grade containers. CDC says FDA-approved food-grade water containers are best. If you cannot get them, use durable, unbreakable containers, not glass.
• Clean them first. Wash with soap, rinse, and sanitize with 1 teaspoon of unscented liquid household bleach in 1 quart (4 cups, about 1 L) of water, as CDC describes. My water storage guide has the full steps.
• Keep it cool and dark. CDC suggests 50°F to 70°F (10°C to 21°C), away from direct sunlight.
• Replace it. If you filled the containers yourself, replace the water every 6 months.

Size matters too. A 7 gal (26 L) container is about as heavy as most people can move, at nearly 60 lb (26 kg). Smaller bottles are easier to carry if you need to leave. Canada.ca suggests including small bottles that are easy to carry in your kit.

Building up to two weeks without a big spend

Two weeks of water all at once can be a lot of money and space. You do not have to do it in one go.

1. Start with 3 days. That is the minimum in both CDC and Canada.ca guidance. For one person it is 3 gallons, or 12 L.
2. Add a container each month until you reach 7 days, then 14.
3. Know your backup. A filter rated for bacteria and protozoa, or unscented bleach, means you can treat water if your stored supply runs low. Only use official figures for treatment. My guide on treating water has them, from CDC, FDA and Health Canada.

Health Canada also suggests replacing emergency supplies every year or by the date on the label, which is a good prompt to check your water and food together.

If your tap water is affected

Stored water is for when the taps stop or the water is not safe. If your area is under a boil-water or do-not-use advisory, follow the local instructions exactly, since they are specific to what is wrong with your supply. CDC suggests checking with your state, local or tribal health department for advice on boiling or treating water in your area. In Canada, your local or provincial health authority issues these advisories.

Next steps

• Use the plan builder to see water alongside food, light and sanitation for your household.
• Read how much water to store for the full comparison of official figures.
• Print the 14-day checklist if two weeks is your goal.