EMERGENCY PREPAREDNESS · CALCULATOR
Spend a Preparedness Budget in the Right Order
Enter the budget, the household size and what each preparedness phase costs you. The planner walks the money through the buying order and shows where it stops, honestly.
Budget reaches
3 of 4phases
4. First aid and comms is short by 30
- 1. Personal 72-hour kits
- 240cumulative 240, covered
- 2. Household water
- 80cumulative 320, covered
- 3. Power and light
- 150cumulative 470, covered
- 4. First aid and comms
- 60cumulative 530, not yet funded
Results update as you type. Phases run in survival order: person, water, power, then the medical and comms layer.
Preparedness money spent without an order is preparedness money half wasted. The bright shiny purchase arrives first, the lantern that will never charge, the gadget that photographs well and feeds nobody. Then the season's budget is gone and the household still cannot cover its first three days.
This planner enforces an order instead. First the personal seventy-two-hour kit for every member, then the household water upgrade, then power and light, then the first-aid and communications layer. That sequence mirrors how emergencies actually take hold, person first, then the home's systems.
Enter what you have and what each phase costs you. The tool walks the money through the phases, stops precisely where the budget stops, and names the shortfall. The output is a buying plan with a next month already sketched.
The formula
Phase one = people x per-person kit; cumulative spend walks phases one to four; remaining = budget - covered phases
- phase
- one buying stage in survival order: personal kits, household water, power and light, then aid and comms.
- cumulative cost
- what each phase plus everything before it asks for. The line where the budget's reach becomes visible.
- budget reach
- the furthest phase fully covered by the money entered. The planner's headline answer.
- shortfall
- what the next phase still needs. Small shortfalls are next month's plan, not reasons to abandon the order.
Why phase order beats price hunting
Emergencies spend your preparedness in a sequence. First the person needs their own water, food, light and warmth. Then the household's stored water runs down. Then the batteries empty. Then someone cuts a finger or the news stops reaching the phone.
Buying in that order means money lands where the event will reach first. The reverse order, a generator before anyone owns a bottle, is the classic expensive failure: impressive gear guarding a household that cannot walk to the car.
The order also deflates panic spending. A budget with a phase list turns every future purchase into a question the planner can answer: is this the current phase, or a shiny detour from it. Most gadgets fail that question in under a second.
And there is a psychology the spreadsheets of the world always miss. Completing phase one for every family member is a visible, finishable win. Wins early in a project are what carry households through the long middle, where most preparedness journeys quietly stall.
- Buy in the order the event will consume your readiness: person, water, power, then aid and comms.
- A phase list answers every future impulse purchase with one question.
- Finishing a phase is the fuel that finishes the project.
Phase one is people, and people is the multiplication
The personal kit scales per head, which is the one budget line households negotiate worst. Four people at sixty is two hundred and forty. That feels large until you list what it quietly includes. The kit holds three days of water and food, a light, a warm layer, and a small aid pouch.
Per-person budgeting also fixes the grab-bag problem. A kit that lives split between two hallway cupboards fails the 2 a.m. test. One bag per person, sized to them, is carried, checked and usable by exactly the person it belongs to.
Children change the maths in both directions. Their kits cost less in litres and food. They cost more in the things adults forget: the comfort item that makes the bag wanted, the duplicate prescriptions, the whistles.
Cost per person is an input, not a verdict. Lean stocking from your normal shop can sit near forty, pre-packed retail bags can double a hundred. Neither figure is a mistake if the phase finishes. The planner reads your honest local prices and keeps moving.
Household phases: water first among the systems
Phase two buys the home's water depth: bulk containers and a filter, stepping the household from bottled days to stored weeks. It lands before power because pipes fail faster than grids in more events, and because thirst outranks every other outage complaint.
The water phase is where this planner's fixed-price inputs shine brightest. Quotes vary wildly by house and jug, so the tool asks what it costs you, not what it should cost someone. Real local prices make the phase map honest.
Power and light, phase three, is the largest single line for many households. A charge bank plus lanterns plus a recharge route, one hundred and fifty to five hundred depending on appetite. It sits after water deliberately: light extends the night, water decides whether there is a day.
The final phase funds the layer with the least impulse support and the highest regret rate: real first aid, the training behind it, and the crank radio. It is chronically last in budgets and chronically missed in events, which is precisely why it is a named phase instead of a suggestion.
Worked example: five hundred for a family of four
The default plan: a budget of five hundred for four people. Kits cost sixty a head, the water upgrade eighty, power and light one hundred and fifty, aid and comms sixty. The phases want two hundred and forty, three hundred and twenty, four hundred and seventy, five hundred and thirty.
The money reaches three full phases and stops at the fourth's door, short by thirty. That is a genuinely strong position: every person equipped, the household's water deepened, the nights covered. One modest next allocation closes the board.
Read the same budget in the other direction and it is a warning too. Spent unordered, five hundred buys one expensive station, some clever gadget, and no kits. Same money, same household, and a worse score on every domain of the gap assessment.
The couple's sample shows the tight-budget shape: one hundred and sixty covers their two personal kits for one hundred and the household water for sixty. Power and comms become next season's map. Phases finished slowly still beat phases abandoned early.
Adjusting prices, pacing the spend, keeping the plan alive
Every phase cost is yours to edit, and the planner recalculates mid-edit. Quote the water phase from your actual containers and the power phase from the bank you are eyeing. Generic averages hide the moment your real budget crosses a phase line.
Pacing beats heroics for most households. One phase per season is a complete plan in just over a year, and the calendar shape makes each stage finishable. The budget does not have to be saved up. It has to be aimed.
Re-run the planner whenever the household changes, because a new member rewrites phase one instantly and raises every following line. The same is true after any phase completes: strike its cost from the inputs and let the freed budget face start the next one.
Finally, keep the tool's output where the household sees it. The short named shortfall, thirty from the radio and course, is the most persuasive shopping list any budget has ever produced. A number with a phase attached gets funded. A feeling does not.
Reference values
The four buying phases and what each one funds
| Phase | Funds | Fails without it |
|---|---|---|
| 1. Personal 72-hour kits | Water, food, light, warmth, aid pouch per person | The first night, the evacuation walk, everyone's own baseline |
| 2. Household water | Bulk containers and a filter beyond bottles | Day four onward, broken pipes, the long boil notice |
| 3. Power and light | Charge bank, lanterns, a recharge route | Every evening after dark, phones, the medical device |
| 4. First aid and comms | A real kit, a course, the emergency radio | The injury nobody was trained for, the briefing nobody heard |
Key terms
- Buying order
- Phasing spend as person, household water, power and light, then aid and comms, matching how events consume readiness.
- Budget reach
- The furthest phase the entered money fully covers. The planner's headline answer.
- Shortfall
- The named amount the next phase still needs. A dated intention rather than an abandoned plan.
- Pacing
- Funding roughly one phase per season. The shape that finishes household preparedness without heroics.
Tips and common mistakes
Field-tested tips
- Quote phase costs from your real basket before entering them. Local prices decide which phase the budget dies at.
- Fund children's kits personally sized. A bag a seven-year-old can carry is the bag that actually leaves the house.
- Close the small shortfall immediately rather than upgrading a finished phase. The board beats the decoration.
- Put the named shortfall on the calendar as next season's allocation. A dated number is a funded number.
Common mistakes
- Buying the impressive gadget first because it sells well, while no household member owns a bottle of water.
- Estimating phases from averages instead of your own quoted prices, then never knowing where the reach stops.
- Funding half of four phases instead of all of two, and holding a household that fails every complete test.
- Treating the plan as finished spending rather than re-running it when the household or the prices change.
Frequently asked questions
What if my budget only covers part of phase one?
Then phase one is the whole plan until it is finished, person by person. Equip the two adults this month and the children next, and let the planner's totals show the family exactly how far the money reached. A half-equipped household is not halfway safe. Completing the first phase is the one stage that cannot be split across categories without breaking the logic.
Why does power cost more than water in most plans?
Because the power phase buys hardware: a battery bank, lanterns, a route to refill both. Water at household scale is jugs and a filter, cheap for the protection it buys. The order therefore puts the cheaper, more urgent system first. That said, the inputs are yours. Quote both phases and the planner will happily show a household where the lines invert.
Is there a sensible per-person cost for a 72-hour kit?
Broadly forty to one hundred in your currency, depending on whether the stock comes from your usual supermarket or from specialist bags. Both can be correct. The planner cares less about the figure than about multiplying it honestly. A sixty-cost kit for four people is a two-hundred-and-forty decision, and that is the number the budget must face.
Should I skip the phases I already partly own?
Partly, and the gap checker is the honest referee. If the shelves genuinely hold three days for every person, set that phase's cost near your true top-up price and let the freed budget reach deeper later. Never zero a phase on memory alone. Stock that has not been counted recently is usually worth less than the household believes, and the phases are cheap insurance against that.
About this calculator
- Written by
- Spare Theory Editorial Team · Research & Testing Desk
- Last reviewed
- 2026-10-16
How we calculatePhases follow the consumption order of common disruptions: personal 72-hour kits, household water storage and filtration, power and lighting, then first aid, training and communications. Cumulative spend walks the phases against the entered budget. All unit costs are user-entered local prices rather than editorial estimates.
Reference basisConsumer guidance on prioritising household emergency spending · Agency checklists for personal and household emergency kits