Reorder Point Calculator
Calculate the inventory level at which you should place a new order to avoid stockouts, based on average daily demand, lead time, and a safety stock buffer.
Results
What is it?
The Reorder Point (ROP) is the inventory level that triggers a new purchase order. When stock drops to the ROP, you order immediately so the replenishment arrives just before the safety stock is consumed. The formula is: ROP = (Average Daily Demand x Lead Time) + Safety Stock. This simple version uses days of demand as the safety stock input — for a statistically rigorous approach, use the dedicated Safety Stock Calculator.
How to use
Enter your average daily demand in units, your typical supplier lead time in days, and the number of days of demand you want as a safety buffer. A conservative safety stock for most products is 7-14 days; fast-moving or critical items may warrant more. The result tells you: when inventory hits this number, place your next order.
Example scenario
Average daily demand: 50 units. Lead time: 14 days. Safety stock: 7 days. Safety stock units = 50 x 7 = 350. Demand during lead time = 50 x 14 = 700. Reorder Point = 700 + 350 = 1,050 units. Days of supply at ROP = 1,050 / 50 = 21 days.
Pro tip
Set up automated alerts in your inventory system to trigger when stock reaches the ROP. Review and update your ROP at least quarterly — demand patterns and lead times shift, and a stale ROP is as dangerous as having none. Pair ROP with EOQ for a complete inventory replenishment policy.