72-Hour Kit Calculator
People to 72-hour water, food, and jugs.
What it does
Emergencies empty shelves in hours, so kits get built in calm weeks. Seventy-two hours of water and no-cook food per person is the standard core: three gallons and thousands of calories that need no stove. Counting beats guessing.
The tool above multiplies people by three gallons of water and age-based calories by three days, then converts water into 6-gallon jugs. Two adults and a kid land at 9 gallons and 16,200 kcal.
FEMA kit guidance with Red Cross checklists sets this same core: a gallon a day per person, canned and dry food, plus meds, documents, cash, light, and radio. Pets, heat, and medical needs stack extras on top.
Pack it, date it, rotate it. Water goes stale, cans expire, kids grow, and prescriptions change, so open every kit yearly. Split supplies across home, car, and work so one stranded bag never strands everyone.
How to use
- Enter adults sheltering.
- Enter kids sheltering.
- Read water gallons for 72 hours.
- Read food kcal for 72 hours.
- Read jug count and pack them.
- Add meds, copies, cash, light, radio.
Formula
- adults
- Adults sheltering, 1 to 20 whole.
- kids
- Kids sheltering, 0 to 20 whole.
People count adults plus kids with age-based daily calories. Jugs assume 6-gallon containers rounded up. Meds, documents, cash, light, and radio ride alongside but compute separately.
Worked example
Example: 2 adults, 1 kid
Two adults and one child for three days.
- Two adults and one kid sheltering 72 hours.
- Water: 3 people x 3 gal = 9 gal.
- Food: (2 x 2000 + 1400) x 3 = 16,200 kcal.
- Jugs: 9 / 6 = 1.5, round up to 2.
- Add meds, copies, cash, and a radio.
Reference table
| Household | Water | Food |
|---|---|---|
| 1 adult | 3 gal | 6,000 kcal |
| 2 adults | 6 gal | 12,000 kcal |
| 2 adults, 1 kid | 9 gal | 16,200 kcal |
| 2 adults, 2 kids | 12 gal | 20,400 kcal |
Limits
- Core supplies only. Meds and needs vary widely.
- 72 hours may fall short in big disasters.
- Storage space and weight limit reality.
- Checklists beat calculators for packing.
Common mistakes
- Storing water once and forgetting it.
- Packing cook-only food with no stove.
- One kit for three locations.
- Skipping meds and documents.
- Ignoring pets in the count.
Try it yourself
Quick checks. Answers sit tucked under each question.
Kit for 1 adult?
Water is 1 x 3 = 3 gal. Food is 2000 x 3 = 6,000 kcal. Jugs: ceil(3/6) = 1.
Kit for 2 adults and 2 kids?
Water is 4 x 3 = 12 gal. Food is (4000 + 2800) x 3 = 20,400 kcal. Jugs: ceil(12/6) = 2.
Questions
How much water per person?
One gallon per person per day for drinking and basic hygiene, plus pets and heat extras. Three people need 9 gallons; store it in 6-gallon jugs that pour sanely.
How much food goes in?
About 2000 kcal per adult and 1400 per child daily of no-cook food: cans, bars, peanut butter, dried fruit. Three days for two adults and a kid totals 16,200 kcal.
Beyond food and water, what packs?
Prescriptions for a week, copies of IDs and policies, cash in small bills, flashlight, batteries, radio, phone bank, wrench, and trash bags. Water and food just start the list.
Do pets need supplies too?
Yes: half a gallon daily per medium pet plus food and a carrier. Service animals pack with the person, not as cargo.
Where do I store the kit?
Cool, dark places with yearly rotation: swap water every 6 to 12 months and food before dates. A stale kit fails exactly when needed.
One kit or several?
Cars, workplaces, and second floors for floods: split supplies so one bag never strands everyone. Meet-up points and out-of-town contacts complete it.