Estimate how many days current inventory can cover at the current sales rate. Use it to turn your own business data into a clear result without building a spreadsheet.
Stock Cover Days Calculator
Test a different scenario
Change any scenario value below. Your original calculation stays unchanged.
Scenario calculations use the same formula and v2.5 validation rules as the main calculator. No scenario values are sent to Borkish.
Calculations and What-If scenarios run in your browser. Borkish does not require you to submit these values to calculate the result.
What the Stock Cover Days Calculator measures
Stock cover converts inventory units into an operational time horizon. Measure ecommerce performance, order economics, marketplace costs and store growth without spreadsheets.
The result is most useful when every input uses the same definitions and reporting period. This keeps comparisons between campaigns, products, customers or time periods meaningful.
When to use this calculator
- Use the Stock Cover Days Calculator to review store economics using order, revenue and customer data.
- Compare product or marketplace performance using the same reporting period.
- Model how changes in conversion, fees or order value affect the business.
Formula
Time-based results depend on consistent period definitions. Make sure the underlying values describe the same operating window.
How to use this calculator
- Inventory Units — enter the value from the same report, forecast or business period as the other inputs.
- Average Daily Unit Sales — enter the value from the same report, forecast or business period as the other inputs.
- Select Calculate. The result updates immediately.
- Compare the output with a previous period, target or relevant internal benchmark before making a decision.
Worked example
Using the demonstration values — Inventory Units = 1000, Average Daily Unit Sales = 25 — the calculator returns 40 days. This example exists only to show how the formula behaves. Replace every demonstration value with your own data before using the result for planning or analysis.
How to interpret the result
Stock cover converts inventory units into an operational time horizon. Use these calculators for store planning, product economics, checkout performance and marketplace decision-making.
A stronger or weaker result does not always mean the underlying business is healthier or worse. Check the definition of Inventory Units, Average Daily Unit Sales, the attribution or accounting rules behind those inputs, and any costs or outcomes that the formula does not include.
Common mistakes to avoid
- Using Inventory Units and Average Daily Unit Sales from different reporting periods or definitions.
- Ignoring marketplace, payment or fulfilment costs when they materially affect the result.
- Using order and customer counts from different periods.
Frequently asked questions
What does this calculator do?
Estimate how many days current inventory can cover at the current sales rate.
Where should I get the input values?
Use your own advertising platform, ecommerce system, accounting report, CRM, analytics platform or forecast—whichever system is authoritative for the metric. Keep all inputs on the same basis and date range.
Is there one good result I should target?
Usually not. A useful target depends on your margins, acquisition model, operating costs, channel, market and business goals. Your own historical performance is often a better starting benchmark than a generic number.
Can I use this for forecasting?
Yes. Enter forecast values to model a scenario, but treat the output as an estimate based on those assumptions rather than a prediction of future performance.
For details about formulas, rounding and limitations, see our Calculator Methodology.