Free calculator
Reorder point calculator.
Enter how many units you sell a day and how long your supplier takes to deliver. The calculator works out the safety stock you need and the stock level at which to place the next order.
In short
The reorder point is the stock count that tells you it is time to order again. Reorder point = lead time demand + safety stock, where lead time demand is average daily sales × average lead time. If you sell 12 units a day, usually wait 5 days for delivery and hold 66 units of safety stock, you reorder when stock falls to 126 units.
Reorder too late and the shelf is empty while you wait for the delivery. Reorder too early and cash sits in the stockroom. The reorder point, sometimes called the reorder level, is the stock level between the two: the moment to order so that new stock arrives before the old runs out, with a cushion for a busy week or a slow supplier.
The calculator above needs four numbers that you can take from your sales history and supplier records. Below, we explain the reorder point formula, how the safety stock is worked out, a worked example and how to turn the result into a low-stock alert.
The reorder point formula
The reorder point has two parts: the stock you expect to sell while you wait for a delivery, and a buffer for when things do not go to plan.
- Lead time demand = average daily sales × average lead time in days
- Safety stock = (busiest day sales × longest lead time) − (average daily sales × average lead time)
- Reorder point = lead time demand + safety stock
Tip. Use the same unit for sales and stock. If you sell single items but order by the case, work in single items and convert to cases at the end.
How the safety stock is calculated
Safety stock protects you against two things: selling faster than usual, and a delivery arriving later than usual. The calculator uses a method that needs no statistics. It takes the worst realistic case, your busiest day's sales repeated over your longest lead time, and subtracts what you expect to sell during a normal lead time. The difference is the extra stock you keep in reserve.
This is often called the average–max formula. It is easy to work out from your own records and it errs on the side of caution, because it assumes your busiest day and your slowest delivery happen at the same time. If that is more cover than a line needs, enter a typical busy day rather than the single busiest day you can remember.
If you set busiest day sales equal to the average and the longest lead time equal to the average, safety stock comes out at zero and the reorder point is simply the lead time demand.
A worked example
A convenience store sells an average of 12 bottles a day of a popular brand of water. Its wholesaler normally delivers in 5 days but has taken as long as 7, and on its busiest day the shop has sold 18.
- Lead time demand: 12 a day × 5 days = 60 bottles.
- Worst realistic case: 18 a day × 7 days = 126 bottles.
- Safety stock: 126 − 60 = 66 bottles.
- Reorder point: 60 + 66 = 126 bottles.
When stock of that line falls to 126 bottles, the shop places its order. In a normal week it will still have about 66 bottles when the delivery arrives. In a bad week, with a rush and a slow delivery, it will just about sell out as the new stock comes in.
With this method the reorder point always equals busiest day sales × longest lead time. Splitting it into lead time demand and safety stock is still useful, because it shows how much of what you hold is a buffer rather than stock you expect to sell.
Where to find the four numbers
- Average daily sales: units sold over a recent period divided by the days you traded. Pick a period that looks like the weeks ahead, not last December for a line that peaks at Christmas.
- Busiest day sales: the most units of the line sold on a single day in that period.
- Average lead time: the usual number of days from placing an order to having stock on the shelf, including time to check and put away the delivery.
- Longest lead time: the longest wait you have had from that supplier recently.
In POS2026, units sold by product and period come from the product and sales reports in Report. Your supplier orders and their delivery status are kept in Purchase, so you can see how long deliveries really take rather than how long the supplier says they take.
When to reorder stock: putting the number to work
A reorder point only helps if someone notices when stock reaches it, and checking every line by eye stops working beyond a few dozen products. That is what low-stock alerts are for.
In POS2026 Stock, set a product's low-stock level to its reorder point. Every sale reduces the count automatically, and when a line falls to that level it is flagged, with alerts also shown on the Dashboard. You then record the supplier order in Purchase, and the stock goes back up when the delivery arrives.
Keep reorder levels up to date
Reorder points go stale. Sales change with the seasons, suppliers change their delivery days, and a line that sold 12 a day in summer may sell 4 in winter. Recalculate for your key lines every few months, and whenever a supplier or a season changes.
- Raise the reorder point ahead of a known busy period, then lower it afterwards.
- If a line can come from more than one supplier, use the lead time of the one you actually order from.
- For perishable stock, keep safety stock low, because waste can cost more than an occasional gap.
- For slow sellers bought in large minimum quantities, the order size matters more than the reorder point.
For a wider view of whether you are holding the right amount of stock, see our guide to retail KPIs, including stock turnover and sell-through.
Questions
Common questions.
Straight answers for shop owners, based on what POS2026 actually does.
What is the reorder point formula?
Reorder point = lead time demand + safety stock. Lead time demand is average daily sales multiplied by the average lead time in days.
How do I calculate safety stock?
A simple method is to multiply your busiest day's sales by your longest lead time, then subtract average daily sales multiplied by average lead time. With 18 × 7 = 126 and 12 × 5 = 60, safety stock is 66 units.
Is a reorder point the same as a reorder level?
Usually, yes. Both describe the quantity on hand that triggers the next order. Some businesses use "reorder level" for the fixed number set on each product in their stock system.
How much safety stock should a small shop hold?
Enough to cover the difference between a normal week and a bad one for that line. Hold more for best sellers that customers expect to find, and less for perishable or slow-moving lines.
Can POS2026 tell me when to reorder?
Yes. Give a product a low-stock level in Stock, and once sales bring the count down to it the line is flagged, with an alert on the Dashboard too. You then record the order with your supplier in Purchase.
Is this reorder point calculator free?
Yes, with no sign-up. Results are rounded up to whole units, because you cannot order part of an item.
Let the shop tell you when to reorder.
POS2026 updates stock with every sale and flags lines that reach their low-stock level. Start a free trial today.
