Book a demo

twelfth · Free calculator

Weeks of cover calculator

Estimate how many weeks the stock you can sell today will last at an expected weekly sales rate. Use it to decide what needs a closer look before the next delivery, not to set an order quantity on its own.

Calculate weeks of cover

How long will the stock on hand last?

Weeks of cover = usable units on hand ÷ expected units sold per week

Weeks of cover
2.00

At this sales rate, stock lasts 2.00 weeks. Cover is only as reliable as the expected weekly sales rate. A stockout or promotion can distort that rate.

See it alongside

Another example: If supplier delivery takes longer than current stock cover, check the reorder point and confirmed stock on order. Read Replenishment →

Download CSV template

Illustrative figures. Change any input to test your own scenario; values stay in this browser page.

How to calculate it

Weeks of cover = usable units on hand ÷ expected units sold per week

  1. Count usable units on hand. Exclude damaged, reserved or otherwise unavailable stock.
  2. Enter expected units sold per week for the same product and location. Adjust a historic rate if stockouts or promotions changed recorded sales.
  3. Divide usable stock by expected weekly sales. Compare that result with the supplier lead time and the stock already on order.

Illustrative example

Thirty units before a two-week delivery

A store has 30 usable units and expects to sell 15 each week. Cover is 30 ÷ 15 = 2 weeks. The supplier normally takes two weeks to deliver, so a fresh order arriving exactly on time leaves no room for a delay or a demand spike.

If 10 units are already confirmed for delivery next week, this simple cover calculation still says two weeks because it only counts stock on hand. Check the delivery date and the reorder point before deciding what to buy.

Check before acting

  • A stockout can depress last week's sales, making cover look longer than it really is.
  • A promotion can change demand quickly; recalculate with the expected promotional rate.

Questions about this calculation

What does two weeks of cover mean?
At the sales rate you entered, today's usable stock would last about two weeks. It is an estimate, not a promise about when the shelf will be empty.
Should stock on order be included?
No. This calculator measures cover from usable stock on hand. Review confirmed inbound stock separately, with its expected arrival date.
Is cover the same as a reorder point?
No. Cover expresses stock as time. A reorder point includes expected demand during delivery lead time and safety stock, then compares that threshold with the stock position.

Keep working with this number

For a list of products, download this calculator’s CSV template or use the Excel workbook. The workbook can be imported into Google Sheets.

For the underlying term, read the glossary explanation. Then compare it with reorder point calculator and sell-through calculator.

← All free retail tools