Quick answer: Count the people, choose the planning duration and calculate each consumable separately. Shared equipment needs a task and runtime plan rather than multiplying every device by the number of people. A commercial kit’s advertised person count cannot replace this calculation.
Set the scope in one line
Write the household members covered, whether supplies stay at home or travel and the chosen duration. Note infants, pets, dietary needs, essential care and expected assistance. These needs may require separate quantities or arrangements.
Use the duration comparison to choose a starting scope. Keep separate entries for home and portable supplies so one stock does not appear to support two plans simultaneously.
Calculate water with the baseline and additional needs
CDC recommends at least one gallon per person per day, initially for three days, and trying to store two weeks where possible. It notes that pregnancy, illness, pets and hot conditions can require more.
For an illustrative four-person, three-day plan, the baseline is 4 × 3 × 1 = 12 US gallons. At fourteen days it is 4 × 14 × 1 = 56 US gallons. These are starting quantities, not a complete allowance for every washing, flushing or individual care task.
Use the water ledger to record additional uses and suitable storage. A treatment device is not itself stored water or proof that an available source can be made safe.
Count actual meals rather than marketing servings
Write the menu, who will eat each meal and what preparation is required. As arithmetic only, four people having three meal occasions daily over three days gives 36 person-meal occasions. That count does not specify calories, nutrition or portion sizes.
Use familiar suitable foods and check individual dietary requirements. A pouch labeled “four servings” may not cover four planned meals. The food quantity guide and pantry checklist turn the menu into inventory.
Estimate consumables from the intended routine
List hygiene and other supplies by user, normal usage and the emergency arrangement. Write quantities in an understandable unit: complete diaper changes, ready battery sets or a particular product quantity. Check that the estimate includes disposal and replenishment rather than only the initial item.
Keep provider-approved medication and care quantities separate. Do not stretch or ration prescribed treatment to make a supply sheet look complete.
Size shared equipment by simultaneous tasks
List who needs portable light, which areas need shared light and which devices must charge. Record the operating time and usable power source. Buying one light per person may still leave an area task uncovered; buying many lights does not solve missing batteries.
Use the energy calculation for larger loads. Subtract the usable quantity already owned from the target to create the gap list. Finish with the category audit and the upkeep record.