Water--
Food calories--
72-Hour Kit Calculator for Emergency Supplies
Build a practical 72-hour supply estimate for a household or shelter bag.
Updated May 2026No signup requiredBuilt for mobile
Formula or method
Water = people x days x gallons per person per day.
Food calories = people x days x calories per person per day.
Worked examples
Basic planning example
Enter realistic values in the 72-Hour Kit Calculator to get a quick planning estimate.
Round-up example
Increase the reserve or waste input to see how the result changes before buying or relying on the estimate.
Practical use cases
- quick planning
- buying supplies
- checking a rough budget
- comparing scenarios
- avoiding shortfalls
Common mistakes
- Using guessed inputs
- forgetting waste or reserve
- mixing units
- treating an estimate as a final quote
FAQ
72-Hour Kit Calculator questions
How accurate is this calculator?
It is a planning estimate based on the values you enter. Real-world conditions can change the result.
Why do results vary?
Overhead, rounding, equipment limits, supplier units, network conditions, and user behavior can all affect the final number.
Should I round up?
Round conservatively when running short would interrupt a project, backup, stream, trip, or outage plan.
What should I do next?
Use the result card and checklist, then compare related calculators or guides before making a final decision.
Does this replace official documentation?
No. Use manufacturer documentation, platform guidance, or professional advice for critical decisions.
72-hour kit planning notes
Start with water
Use at least one gallon per person per day as a baseline, then add more for heat, pets, illness, cooking, and sanitation.
Plan food by people and days
Meals, snacks, infant needs, medical diets, and pet food should be counted separately instead of guessed at the end.
Keep the kit realistic
A good kit is one you can store, find quickly, and actually use when power, roads, or stores are unavailable.