Grocery reusable bag demand calculator

Calculate expected bag use and days until stock exhaustion with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Use expected bag use and days until stock exhaustion to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Transactions per day (count/day)
200
Measured bags per transaction
0.3
Usable bag stock (count)
500
Supplier lead time (days)
3
Expected bag use (bags/day)
60
Days until stock exhaustion
8.333333
Latest reorder day from now
5

Try another scenario

Transactions per day (count/day)
250
Measured bags per transaction
0.4
Usable bag stock (count)
600
Supplier lead time (days)
4
Expected bag use (bags/day)
100
Days until stock exhaustion
6
Latest reorder day from now
2
Calculation method

Calculation method

Expected bag use (bags/day)

Transactions×bags per transaction.

Days until stock exhaustion

Stock/daily use; zero-use case returns exact text.

Latest reorder day from now

floor(stock/daily use−lead); negative means order already late; zero-use case text.

Symbols and units
a
Transactions per day (count/day)
b
Measured bags per transaction
c
Usable bag stock (count)
d
Supplier lead time (days)

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • Constant bag uptake per transaction and daily transaction forecast; deterministic stock exhaustion. Supported limits: All numeric inputs and computed intermediates must remain finite. Supported numeric input magnitude is zero or 1e-12 through 1e12 in absolute value; reject values outside this bounded range. All lists/JSON record tables are limited to 100 records unless a stricter bound is stated; reject malformed record arity and wrong member types. All numeric values must be finite. Lists contain at most 100 records; required lists must be nonempty. Rates, probabilities and fractions are entered as fractions, not percentages; fractions must be between 0 and 1. Use a single consistent user-selected currency for all amounts; no exchange-rate conversion.
Are these inputs private?

These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.

Share this page
Share this calculator

Leave unchecked to share the page without your entered values.