Your reorder point is the stock level at which you should place a new purchase order — low enough not to overstock, high enough that you don't run out while the next shipment is on its way. Use the free calculator below, then see the formula and how to automate it.
= (5 × 14) + 15 units
The reorder point formula
Reorder point = (sales per day × lead time in days) + safety stock
- Sales per day — your average daily sales for the product (use a recent 30–60 day window).
- Lead time — days from placing the order to stock on the shelf (include processing, shipping and receiving).
- Safety stock — a buffer for demand spikes and late deliveries. A simple rule: a few days of average sales.
Worked example
Sells 5/day, lead time 14 days, safety stock 15 units → reorder point = (5 × 14) + 15 = 85 units. When stock on hand drops to 85, place your next order.
How much to order
The reorder point tells you when; order quantity tells you how much. A simple approach is to cover a fixed period — e.g. 30 days: order quantity = sales per day × 30. Tune it to your cash flow, storage and supplier minimums.
Automate it across every product
Calculating this by hand for one product is easy; doing it for hundreds, with changing demand and different suppliers, is not. Foreshelf computes the reorder point for every product automatically from your Shopify sales history, flags the ones that have hit it, and emails you a daily digest — so you never miss a reorder. See the full method in our guide onhow to forecast inventory on Shopify.