Enrichment · Life Skills

A gallon a day, for everyone in the house.

Count the people and pets in your home and pick how many days to plan for. The calculator shows how much water to store, how far what you already have will go, when stored water is due to be replaced, and how to treat water if the supply runs out.

Plan the waterWhat you get

The calculator

The worked example is three people, a dog and a cat with some water already stored. Change any number and the plan follows. Nothing you type leaves this browser.

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What you get

Enrichment · Life SkillsFree

What you finish with
A water plan for your own household: gallons to store for the days you choose, the 3-day minimum and the 2-week goal, how many days your current supply covers and what it would take to close the gap, replacement dates for stored water, a printable plan with the bleach table, and a calendar file of reminders.
Who it is for
Anyone setting up a first apartment or a family emergency kit, students in life skills, health and emergency preparedness classes, and the teachers and community groups who run preparedness lessons.
Format
Browser tool. Works on a phone or computer. Print or save as PDF, a calendar file (.ics) of replacement dates, a .csv spreadsheet, and a file to move the plan between devices.
Access
Free. No account and no sign-in. Your household details stay in this browser; nothing is sent to Caveat.
Where it lives
The Life Skills space in Caveat Enrichment.
Support
Questions, a correction or a request: team@caveatacademic.com.
The planning rule from Ready.gov and the CDC. The gallon covers drinking, preparing food and basic washing.

How to use it

  1. Count the adults, children and babies in the home, and add each pet with its weight.
  2. Pick the days to plan for. Start with three; work toward two weeks.
  3. List the water you already have: the container, how many, whether you filled it or bought it sealed, and the date.
  4. Read the plan: gallons to store, days covered, and what would close the gap. Check the replacement dates.
  5. Print the plan with the bleach table and keep it with the water. Save the calendar file so the reminder finds you.

Plan the water

Where the numbers come from

Planning figures from federal emergency guidance, plus two allowances this calculator states plainly.

The planning figures

  • One gallon per person per day, for drinking and sanitation, for at least 3 days; a 2-week supply if you can store it. Babies and children count as people.
  • Very hot weather can double the water a person needs, so the hot-weather switch plans 2 gallons per person per day.
  • Pregnant, nursing or ill: official guidance says to store more without giving a number. This calculator adds half a gallon a day for each such person. That figure is our planning allowance, not an official one.
  • Pets: one fluid ounce per pound of body weight per day, a common veterinary rule of thumb for dogs. It is used here for cats too, which need a little less. There are 128 fluid ounces in a gallon.
  • Weight: a gallon of water weighs about 8.34 pounds, so a full 5-gallon jug is about 42 pounds before the container.

Storing it

  • Unopened store-bought water is the safest and most reliable choice. Keep it sealed and go by the date on the label.
  • To fill your own, use food-grade containers with tight lids, not jugs that held milk or juice or anything toxic. Wash them, then sanitize with 1 teaspoon of unscented household bleach in 1 quart of water: shake it over every inside surface, wait 30 seconds, pour it out and let the container air-dry.
  • Label each container "drinking water" with the date, and replace home-filled water every 6 months.
  • Store water somewhere cool and out of direct sunlight, away from gasoline, pesticides and other chemicals.
  • In an emergency, the water heater tank, melted ice cubes and the liquid in canned fruit and vegetables are safe extra sources. Never drink from a toilet bowl, a radiator or a home heating boiler, and keep pool and spa water for washing. The CDC allows water from a toilet tank if it is clear and no cleaner has been added; an older FEMA brochure says to leave it.
Water to disinfect6% bleach8.25% bleachCloudy, colored or very cold: 6%Cloudy, colored or very cold: 8.25%
1 quart or 1 liter2 drops2 drops4 drops4 drops
1 gallon8 drops6 drops16 drops12 drops
2 gallons16 drops (1/4 teaspoon)12 drops (1/8 teaspoon)32 drops (1/2 teaspoon)24 drops (1/4 teaspoon)
4 gallons1/3 teaspoon1/4 teaspoon2/3 teaspoon1/2 teaspoon
8 gallons2/3 teaspoon1/2 teaspoon1 1/3 teaspoons1 teaspoon

The first two columns are the U.S. EPA table for regular, unscented household bleach. The last two are those amounts doubled, as the EPA directs for cloudy, colored or very cold water. For any bleach labeled between 5% and 9%, the CDC gives one rule: 2 drops for a quart, 8 drops for a gallon and 40 drops (half a teaspoon) for 5 gallons, doubled for cloudy or very cold water. For other strengths, follow the label or your local health department.

The worked example, checked when the page is built. Two adults and a child need 3 gallons a day. A 54-pound dog and a 10-pound cat, at one fluid ounce per pound, add 64 fluid ounces, which is half a gallon. That is 3.5 gallons a day: 10.5 gallons for three days and 49 gallons for two weeks, about 409 pounds of water. Four 5-gallon jugs, three cases of 24 half-liter bottles (3.17 gallons a case) and six 1-gallon jugs hold 35.5 gallons, enough for 10 full days, so the home is 13.5 gallons short of two weeks: 3 more 5-gallon jugs.

Sources

  1. Federal Emergency Management Agency, Ready.gov, "Water" and "Build A Kit": one gallon per person per day for several days; needs vary with age, health, activity and climate; very hot temperatures can double the water needed.
  2. Centers for Disease Control and Prevention, "Creating and Storing an Emergency Water Supply": at least 1 gallon per person per day for 3 days, a 2-week supply if possible; sanitizing containers; replacing stored water every 6 months; where to store it.
  3. U.S. Environmental Protection Agency, "Emergency Disinfection of Drinking Water": boiling for 1 minute (3 minutes above 5,000 feet) and the bleach table for 6% and 8.25% sodium hypochlorite, doubled for cloudy, colored or very cold water.
  4. Centers for Disease Control and Prevention, "How to Make Water Safe in an Emergency": boiling (3 minutes above 6,500 feet), one bleach rule for strengths from 5% to 9%, and the warning that boiling and disinfecting cannot make water with fuel or toxic chemicals safe.
  5. Centers for Disease Control and Prevention, "How to Find Clean Water in an Emergency," and Federal Emergency Management Agency and American Red Cross, Food and Water in an Emergency (FEMA 477): sources of water inside a home, and which ones are not for drinking.
  6. PetMD, "How Much Water Should a Dog Drink?" (reviewed by a board-certified veterinary nutritionist): about 1 ounce of water per pound of body weight each day. The CDC advises storing extra water for pets without giving an amount.

General preparedness information for learning and planning, not medical advice or official emergency instructions. In an emergency, follow your local officials and water utility. People with medical conditions should ask their doctor how much water to store. The worked example is made up. Support: team@caveatacademic.com.