How much water does a family of 4 need for a month?

The short answer

A hundred and twenty gallons, which weighs about 1,000 pounds. This is the point where storing more stops being the sensible answer.

120

Gallons

1,001 lb

What it weighs

7-gallon jugs

Half a ton of water, and the first page here that tells you to stop buying containers

A hundred and twenty gallons is two and a bit fifty-five gallon drums, or seventeen jugs, and roughly half a ton sitting in your house permanently. It can be done and some households do it. For most people it is the wrong purchase, because the same money spent on a way to make water safe covers a month, a year and every year after that, while another drum covers thirty days once. Past about two weeks the question quietly changes from how much can I keep to where will more come from, and nobody selling drums has any reason to tell you that.

What replaces the extra drums

Two things, and you want both. A way to treat water you did not store, which for most households means a gravity filter rated for bacteria and protozoa, since those are what make people ill in a domestic supply failure. And a known source you have actually looked at, which might be a river, a pond, a rainwater butt, a neighbour's pool or the fifty gallons already sitting in your own water heater. Knowing which one, and how you would carry from it, is the part people skip. Water weighs 8.34 pounds a gallon, so a round trip carrying five gallons is forty-two pounds each way.

Store the two weeks, plan the rest

The arrangement that works for most families of four is fifty-six stored gallons, a filter, and a source they have walked to. That covers a fortnight without touching anything questionable, and then extends indefinitely at a few gallons a day. It costs less than the extra drums, takes up a quarter of the space, and does not fail on day thirty-one the way a pure storage plan does.

Keep track of your 120 gallons as you actually buy them.

Provision Planner counts the water already in your house against the target on this page, and tells you how many days you really cover. Your household and gallon figure carry across, so there is nothing to type in twice.

See how many days you cover

The next questions, answered

Is it realistic to store a month of water for a family of 4?

It is possible and it is usually the wrong spend. A hundred and twenty gallons is about half a ton and covers thirty days once. A filter and a known source cost less, take less room, and do not run out.

How much water should a family of 4 actually store?

Fifty-six gallons, two weeks, is the figure most households should aim at. Past that, put the money into a way of treating water and a source you have actually identified rather than into more containers.

Water is one part of it. See the full supply plan for this household, which covers the food alongside it.