When should you reorder inventory? This inventory reorder calculator estimates your reorder point, how many days of stock remain, and whether you are at risk of running out before your next delivery arrives.
How to use this calculator
- Enter current inventory on hand.
- Enter average daily sales and supplier lead time in days.
- Add safety stock and your typical reorder quantity.
- Review reorder point, stockout timing, and risk level.
Formula
Reorder point = (Average daily sales × Lead time days) + Safety stock. Days until stockout = Current inventory ÷ Average daily sales.
Example
With 85 units on hand, 12 sold per day, 7-day lead time, and 20 units of safety stock, the reorder point is 104 units — meaning you should reorder now because inventory is below that level.
Frequently asked questions
- What is a reorder point?
- It is the inventory level where you should place a new order so you do not run out while waiting for the supplier.
- What is safety stock?
- Extra units kept as a buffer for sales spikes or supplier delays.