Reorder Point Calculator
When do I need to reorder to avoid running out?
Your numbers
Result
Reorder point
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How this is calculated
The reorder point is the inventory level at which you must place a new purchase order to avoid a stockout during the lead time. Working it out properly is what separates a store that grows from one that keeps losing its ranking every time it goes out of stock.
- Demand during lead time = average daily sales × lead time in days
- Safety stock = average daily sales × safety stock days
- Reorder point = demand during lead time + safety stock
- Days of cover = units on hand ÷ average daily sales
- Suggested order quantity = daily sales × (lead time + safety days + 30 days of forward cover)
What to make of the number
Stockouts cost more than the lost sales. On marketplaces, running out interrupts sales velocity, which damages organic rank, which means the recovery takes weeks after stock arrives. Most experienced sellers carry noticeably more safety stock than the arithmetic alone suggests for exactly this reason.
Frequently asked questions
What is a reorder point?
The inventory level that triggers a new purchase order. It is set so that the stock you have left covers demand during the supplier lead time, plus a safety buffer for demand that runs higher than average.
How much safety stock do I need?
Enough to cover demand variability during lead time. As a starting point, two to four weeks of average sales is common; products with spiky or seasonal demand need more, and products with reliable, flat demand need less.
What if lead times are unreliable?
Base the calculation on your worst realistic lead time rather than the average. A supplier who quotes 30 days and delivers in 45 will cause stockouts if you plan around 30.
Should I use average daily sales or recent sales?
Recent is usually better for fast-growing or seasonal products. Using a trailing annual average during a growth phase will set the reorder point too low and you will stock out repeatedly.
How does the minimum order quantity affect this?
MOQ sets the floor on order size, not on timing. Order at the reorder point, but never order less than the MOQ — if the MOQ is large relative to demand, factor the extra carrying cost into your unit economics.