How do you calculate a reorder point?
Multiply average daily usage by the lead time in days to get demand during the wait, then add safety stock. The result is the stock level at which a new order must be placed to avoid running out before the replenishment arrives.
Reorder Point Calculator formula
Reorder point = (Average daily usage x Lead time in days) + Safety stock
Worked example: Selling 20 units a day with a 14 day lead time and 60 units of safety stock gives a reorder point of 340 units.
How this works in your browser
Reorder point is daily usage times lead time, plus safety stock. The demand-during-lead-time term is the part that does the work: it answers how much you will consume between raising an order and receiving it, which is the entire window in which a stockout can occur. Safety stock is then a separate buffer against variability rather than being baked into the average, which is what lets you tune the two independently. All arithmetic runs in your browser.
Who uses Reorder Point Calculator
Avoiding stockouts
Know exactly when to reorder rather than checking shelves by eye.
Setting system triggers
Configure reorder alerts in your stock software with a defensible number.
Managing long lead times
See how much earlier you must order when a supplier is slow.
Reducing overstock
Stop ordering too early and tying up cash in shelves.
Frequently asked questions
How is the reorder point calculated?
Average daily usage multiplied by lead time in days, plus safety stock. The first part covers what you will sell while waiting for delivery; the safety stock covers the days the forecast or the supplier lets you down.
How much safety stock should I hold?
Enough to cover the variability you actually see, not a round number. If demand or lead time swings widely, you need more; if both are steady, you need little. Holding safety stock is not free, so treat it as insurance priced against the cost of a stockout.
What lead time should I use?
The realistic worst case rather than the supplier's quoted best case, and measured from when you raise the order to when stock is on your shelf and sellable. Quoted lead times routinely exclude your own goods-in processing, which is where the extra days hide.
Does this handle seasonal demand?
Not directly, since it uses one average daily usage figure. For seasonal products, recalculate using the usage rate for the period you are ordering into rather than a twelve-month average, otherwise you will under-order before a peak.
Are my figures uploaded?
No. The calculation runs entirely in your browser.