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Everyday living

How long will my household supplies last?

Estimate how long toilet paper, detergent, shampoo, drinking water, rice, or gas will last using the amount remaining and your household's actual use.

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Formula version 3.0.0 · Last reviewed 2026-10-06

One calculator · six household supplies

Which supply do you want to check?

Changing the supply switches its units and example together.

Selected supply · Gas cylinder

How long will my gas cylinder last?

Use remaining fuel mass—excluding the cylinder itself—and appliance consumption to estimate continuous hours and scheduled days.

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Calculator inputs and results

Input guide

Inputs

The initial values are examples. Replace them with your situation, then calculate.

When possible, subtract the empty cylinder's tare mass from total weight.Input unit: g or kg
Choose grams or kilograms to match the remaining amount.
g/h
Check the manual for a rate matching the planned output setting.
hours/day
Converts continuous hours into days on your schedule.
Open advanced settings
%
Accounts for burner setting and environmental variation.Estimated example value — you can edit it

Check your inputs, then calculate

Ready when you are

Replace the example inputs with your own, then select Calculate to see the result and reasoning.

Formula and assumptions

Choose a supply and enter the amount remaining and your household's actual use. Compare the estimated duration with the range for higher or lower use to plan your next purchase.

Every option uses one shared engine: remaining stock divided by consumption in the same base unit. The selection changes only the fields and units; usage variation changes the rate to produce a duration range.

Why the result can vary

Product specifications, measurement error, household habits, travel, meals out, weather, and burner settings can change the real run-out time. The range is an input sensitivity, not a statistical guarantee.

Example

One method from toilet paper to rice

Inputs: For 12 toilet-paper rolls, enter sheets per roll and daily use; for 10kg of rice, enter people and dry grams per day

Outcome: See the selected supply's duration, consumption rate, and estimated depletion date in the same workspace.

Cautions

  • Water results are not medical hydration advice, and rice inputs use uncooked dry mass.
  • Gas calculations estimate fuel quantity only; follow product and local guidance for compatibility, ventilation, leaks, and storage.

Frequently asked questions

Are toilet paper, detergent, shampoo, water, rice, and gas all calculated on one page?

Yes. Changing the option switches the shared stock-duration engine to the appropriate fields, units, and explanation. Values from different supplies are never mixed in one calculation.

How do I estimate how many days my toilet paper will last?

Multiply rolls remaining by sheets per roll, then divide by the household's daily sheet use. Count a partly used roll as a decimal, such as 0.5. Check the package because rolls contain different sheet counts.

How many washes or days will detergent and shampoo last?

Divide the remaining amount by the amount used per wash, using milliliters for liquids or grams for powder detergent. Then use household size and weekly washing frequency to estimate days. Measure your product's dose or pump volume for a better estimate.

How should household size affect water and rice?

For water, use the household's total liters per day. For rice, use uncooked dry grams per person per day times household size. The water option does not prescribe medical hydration needs.

Does a gas cylinder show hours instead of days?

Yes. Remaining fuel mass is divided by fuel used per hour. Flame setting, temperature, and appliance efficiency can change actual runtime.

Is the calculated day or hour an exact run-out time?

No. It is a planning estimate assuming the entered average continues. Use realistic stock and variation inputs to reflect changing use.

Household supply duration calculator guide

Choose toilet paper, detergent, shampoo, water, rice, or gas to estimate the days or hours your remaining supply can cover before the next purchase.

  • Choose the item first and match stock and usage units. Keep dry rice and cooked rice weights distinct.
  • Include everyone sharing the supply and the usage schedule. For gas, exclude the empty cylinder's weight.

Guide updated