Stock cover calculator
Enter the quantity on hand and your average daily, weekly or monthly sales to know when to reorder from your supplier.
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How to use it
- Enter stock on hand, average sales, sales per and start date.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Daily sales = sales ÷ days in the period (1, 7 or 30). Days of cover = stock ÷ daily sales. Run-out date = start date + whole days of cover.
Example
Inputs: Stock on hand = 1,200 units, Average sales = 300 units, Sales per = Week, Start date = 2026-10-01. Result: Days of cover: 28 days; Weeks of cover: 4 weeks; Expected run-out date: Thursday, October 29, 2026 (2026-10-29).
Limits and caveats
- It assumes sales continue at the same rate; seasons and promotions change the result.
- A month is taken as 30 days, and stock already on order is not counted.
Questions about this tool
When should I reorder?
At least one lead time before the run-out date, plus a margin for safety stock.
How is stock cover different from turnover?
Cover looks ahead at how long current stock lasts, while turnover measures what happened in a past period.
Should I enter units or value?
Use the same unit for stock and sales, either units for both or value for both.