A store can show 100 units on the shelf and still have fewer units available for new orders. Reservations consume part of that stock. The Stock Coverage Calculator starts with available units, then compares their estimated runway with your supplier lead time.
Remove committed units first
Enter 100 units on hand and ten reserved units. Available stock is 90. With average demand of five units daily, estimated coverage is 18 days.
Use a seven day lead time. Expected demand during that wait is 35 units, leaving a lead time cushion of 55 units. This cushion describes the current available stock after the entered lead time demand; it is not automatically a separate safety stock policy.
Daily demand must mean the same thing as the stock count
If a promotion supplies free units, include those units in the consumption assumption. Counting only paid orders can overstate how long physical stock will last. BOGO & Multi Buy Profit Calculator shows how many units an entered paid and free group supplies.
Use a daily average suited to the period you are planning. An average from a quiet month may not describe a busy campaign. The calculator extrapolates your entered rate and does not predict changing demand, weekend patterns or seasonal peaks.
Incoming stock is not available before it arrives
This tool examines current on hand and reserved units. An expected supplier shipment should not be added to today’s available stock merely because it has been paid for. Review its arrival separately and check whether the current runway reaches that date.
For a replenishment position that includes incoming units, Reorder Point & Quantity Calculator provides a separate model. The two results can differ for a good reason: one measures stock available now, and the other helps determine whether another purchase is triggered.
Handle zero demand and over reservation honestly
If daily demand is zero, there is no finite days coverage estimate from division by demand. The calculator leaves runway undefined. It does not promise the stock can never become obsolete or that future demand will remain zero.
Reservations greater than on hand stock are rejected instead of creating misleading negative availability. Correct the count or identify commitments that belong to incoming stock outside this input. Before relying on a coverage result, reconcile damaged, returned and unavailable units with the physical count. A spreadsheet balance cannot replace that stock check.