Reorder Point Calculator

A reorder point (ROP) is the inventory level at which a new purchase order should be placed to replenish stock before it runs out. It accounts for both your average consumption rate and the time it takes for new stock to arrive, plus a safety buffer to handle demand spikes or supplier delays.

The Reorder Point Formula

The reorder point formula is ROP = (Avg Daily Usage × Lead Time) + Safety Stock, where safety stock is calculated as (Max Daily Usage - Avg Daily Usage) × Lead Time. This approach uses your worst-case demand scenario to determine how much buffer inventory you need.

• Max Daily Usage — The highest number of units you sell or consume in a single day. This represents your peak demand scenario.
• Average Daily Usage — The typical number of units sold or consumed per day, averaged over a representative period.
• Lead Time — The number of days between placing a purchase order and receiving the goods into your warehouse.

Reorder Point vs Safety Stock

Safety stock and reorder point are related but distinct concepts. Safety stock is the extra inventory held as a buffer against uncertainty — it protects you when demand exceeds your average or when suppliers deliver late. The reorder point, on the other hand, is the trigger level that tells you when to place a new order. Your reorder point includes both the inventory you expect to sell during lead time and your safety stock cushion.

How Nventory Helps

Nventory continuously monitors your stock levels across every sales channel and warehouse. When inventory for any SKU drops to its reorder point, Nventory automatically sends alerts and can even generate draft purchase orders — so you never miss a reorder window. With real-time demand tracking and supplier lead time analytics, your reorder points stay accurate as your business evolves.