Reorder point and stockout calculator
Enter how fast a product sells, how long your supplier takes and how much stock you have. You get the sell-out date, the reorder point and the day to order by.
How the calculator works
It uses the standard reorder point formula. Reorder point = units sold per day × (lead time + safety stock days). When stock falls to that level, you order, and the delivery lands as the buffer starts to be used.
- Sells out in is stock on hand divided by units sold per day, if sales carry on at the same rate.
- Order by is the sell-out date minus the lead time and the safety days.
The weak spot is the daily rate. A single average hides weekends, promotions and seasons, so recalculate after a sale or when a product starts selling faster. For the whole method, read how to set reorder points in WooCommerce.
Common questions
What is a reorder point?
The reorder point is the stock level at which you place a new order, so the delivery arrives before you run out. It is the average units sold per day multiplied by the supplier lead time in days, plus any safety stock.
How do I find average daily sales in WooCommerce?
Open Analytics › Products, set the date range to the last 30 days and read the product’s items sold. Divide by 30. Use a recent window: a product that sold faster this month will run out sooner than its yearly average suggests.
How much safety stock should I keep?
Many small stores keep a few days of sales as a buffer, more for products with slow or unreliable suppliers and fewer for products that are easy to restock. Raise it if you have run out before, and lower it if stock sits for months.