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Reorder before the stockout, not after.
Out-of-stock does not just lose the sale. It drops you out of Google Shopping and AI shopping results, and getting momentum back takes weeks. I built the inventory system for the brand I run ops for; this is the same math it uses.
-Safety stock (units)
-Reorder point (units)
-Days until reorder
The formula
Safety stock = (max daily sales × max lead time) − (avg daily sales × avg lead time). It absorbs the double bad luck of a demand spike during a supplier delay.
Reorder point = (avg daily sales × avg lead time) + safety stock. When on-hand crosses this number, place the PO that day, not next week.
Common questions
How do I calculate a reorder point?
(Average daily sales × lead time) + safety stock. This tool computes both parts from four numbers you already know.
Why does stocking out hurt more than the missed sales?
Out-of-stock products get filtered out of Google Shopping and AI shopping results, ad sets pointing at them burn money, and rankings take time to recover after restock. Staying in stock is a visibility strategy, not just an ops one.
My lead times vary wildly. What do I enter?
Use the real average for the average field and your worst genuine delay for the max. If the spread is huge, the tool will show a big safety stock, and that is the honest cost of an unreliable supplier: it prices the risk into inventory.
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