Reorder Point Calculator
This reorder point calculator tells you when to place a new order. Enter daily demand, supplier lead time, and safety stock, and the reorder point calculator returns the reorder point (ROP), the stock level at which you should reorder. It is the standard way of calculating reorder level for any inventory item.
Results
The Reorder Point Calculator is part of our Inventory collection. Browse more inventory to size, convert, and check your work alongside this tool.
What the reorder point calculator shows
A new order takes time to arrive, so you have to order before stock runs out. The reorder point calculator finds the stock level that covers demand during the lead time plus a safety buffer. When stock falls to that inventory reorder level, it is time to order.
Reorder point formula calculator
The reorder point formula calculator adds lead time demand and safety stock:
Lead time demand covers the stock you expect to sell while waiting for delivery; safety stock covers the days when demand is higher or delivery is late. This is how to calculate reorder point with safety stock.
Calculating reorder level: example
An item sells 40 units a day, the supplier takes 7 days, and you keep 100 units of safety stock. The reorder point calculator gives:
So reorder when stock falls to 380 units.
How to use the ROP calculator
Enter the average daily demand in units, the lead time in days from order to delivery, and the safety stock. The ROP calculator returns the reorder point, the demand during the lead time, and the safety stock. Use working days for both demand and lead time if your stock only moves on working days.
Reading the reorder level calculator result
The reorder point is a trigger level, not an order size. When on-hand plus on-order stock falls to it, place an order. The order size itself comes from the economic order quantity. If you run out often, raise the safety stock; if stock sits for weeks, lower it.
When to use the inventory reorder point calculator
- Setting min levels in an inventory system
- Planning stock for a new product
- Adjusting the reorder stock level after a supplier change
- Using the inventory reorder point calculator for seasonal items
Common reorder point calculator mistakes
- Ignoring stock on order. Count incoming stock to avoid duplicates.
- Mixing calendar and working days. Keep demand and lead time in the same units.
- Zero safety stock. Any delay then causes a stockout.
Tips for accurate results
- Use recent demand, not last year's average.
- Track real supplier lead times, not quoted ones.
- Review reorder points every quarter.
Calculate the reorder point when demand varies
Average demand hides swings. To calculate the reorder point for a variable item, use average daily demand for lead time demand and size the safety stock from the variation, often with a service level and the standard deviation of demand. Longer lead times need more buffer because there is more time for demand to drift. Reorder quantities are often set in whole pallets, which the pallet calculator helps with.
Inventory order point vs fixed schedule
An inventory order point system orders whenever stock hits the trigger, so order dates vary while quantities stay fixed. A periodic system orders on a fixed calendar with varying quantities. The reorder point approach responds faster to demand changes and suits items with steady supply.
Reorder point calculator reference
| Daily demand | Lead time | Safety stock | ROP |
|---|---|---|---|
| 10 | 5 days | 20 | 70 |
| 40 | 7 days | 100 | 380 |
| 100 | 14 days | 300 | 1,700 |
Reorder Point Calculator FAQ
What is the reorder point formula?
ROP = daily demand × lead time + safety stock.
What is the difference between reorder point and EOQ?
The reorder point says when to order; EOQ says how much to order.
How do I calculate reorder point with safety stock?
Add the safety stock to lead time demand. Without a buffer, ROP equals daily demand times lead time.
Should I count stock on order?
Yes. Compare on-hand plus on-order stock with the reorder point to avoid double ordering.