Emergency Kit Sizing Calculator

Work out emergency kit sizing instantly with clear inputs, formula shown and shareable results.

About Emergency Kit Sizing Calculator

Water follows the 3.8 litres per person per day guidance, food is sized by energy and converted at about 3,500 kcal per kilogram of shelf stable food, plus 1.5 kg of sundries per person. Total kit weight decides whether a kit is a grab bag or a stored cache, and a three day kit for four is already too heavy to carry far.

Formulas

Water

litres = people x days x 3.8

Food weight

kg = people x days x kcal per day / 3500

Worked example

With the default values below, Emergency Kit Sizing Calculator returns Water to store of 45.6. Change any input above and every figure here is recalculated in your browser.

Inputs used

People in the householdminimum 1: 4
Days of self sufficiencyminimum 1: 3
Energy per person per dayminimum 100 kcal: 2,000 kcal

Results

Water to store: 45.6 L
Total food energy needed: 24,000 kcal
Food weight at 3,500 kcal per kg: 6.86 kg
Total kit weight including sundries: 58.5 kg

Step by step

1Values used
2Water
3Food weight
4Water to store= 45.6 L
5Total food energy needed= 24,000 kcal
6Food weight at 3,500 kcal per kg= 6.86 kg
7Total kit weight including sundries= 58.5 kg

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Emergency Kit Sizing figure worked out?

litres = people x days x 3.8. Water follows the 3.8 litres per person per day guidance, food is sized by energy and converted at about 3,500 kcal per kilogram of shelf stable food, plus 1.5 kg of sundries per person.

Why does this matter?

Total kit weight decides whether a kit is a grab bag or a stored cache, and a three day kit for four is already too heavy to carry far.

What do I need to enter?

Enter people in the household, days of self sufficiency, energy per person per day. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.