How much water should you store for an emergency?

Water is the most important thing in any emergency kit. People can go much longer without food than without water, and water also matters for medication, babies, hygiene and pets. The question is how much, and where to keep it. The calculator above works it out for your household.

What official guidance in Ireland says

Drinking water versus everything else

It helps to separate two kinds of water:

• Drinking water is what people drink, and what babies' formula and medication need. This is the figure official guidance and the calculator focus on.
• Other water is for washing, flushing and cleaning. It doesn't need to be drinking quality, but you'll need more of it than you expect.

Pets need their own drinking water, and hot weather, illness, pregnancy and breastfeeding all increase what people need.

Working out your household's water

SupKit plans on 3 litres of drinking water per person per day for up to two weeks, the same figure the app uses. Here's what that adds up to:

Drinking water at SupKit's planning figure of 3 L per person per day. SupKit estimate

Add your pets with the pet water calculator.

Storage options

• Shop-bought bottled water is the simplest option: it's sealed, dated and easy to rotate.
• Food-grade containers you fill yourself save space and money; keep them clean, sealed and labelled with the date you filled them.
• Keep it cool and dark, away from sunlight, heat and chemicals, and off the floor of garages and sheds.

Keeping it fresh

Check stored water regularly. Use or replace bottled water before its date, and refresh water you've stored yourself as official guidance recommends. Use the old water for plants or cleaning rather than pouring it away.

What if you can't store it all?

Space is the most common problem. Filters, purification tablets and boiling can make some water safer to drink, but they need a suitable source of water to work, and none of them can create water when the taps stop completely. Our guide to alternatives to bottled water explains what each can and can't do.

Water for babies, pets and medical needs

• Babies: if a baby uses formula, plan for the water it needs, and follow official advice on making up feeds, especially during a boil water notice.
• Pets: dogs and cats need their own water every day; the pet water calculator gives a figure for each animal.
• Medical needs: some medicines, devices and conditions need extra water. Ask your doctor or pharmacist if you're unsure.
• Hot weather and illness: people need more water when it's hot or when they're unwell.

Common mistakes

• Counting water for washing as drinking water. Keep the two separate in your plan.
• Forgetting pets.
• Storing water somewhere warm or sunny, such as a garage that heats up in summer.
• Never refreshing it. Stored water needs checking and replacing.
• Relying only on filters or tablets, which don't help if the taps stop completely.

Use the calculator

The calculator at the top of this page uses your household, your pets and the number of days you choose. SupKit keeps track of the water you've stored and reminds you before it's due for replacing.