Reorder Point Calculator
Work out exactly when to reorder: average daily demand × lead time + safety stock, with the math shown and edge cases explained.
Don't have this number? Compute it with the safety stock calculator below.
When on-hand + on-order inventory drops to the reorder point, place a new order: the lead-time demand gets consumed while you wait, and the safety stock absorbs surprises. Compute the buffer with the safety stock calculator and the order size with the EOQ calculator.
Frequently asked questions
What is the reorder point formula?
Reorder point = (average daily demand × lead time in days) + safety stock. Selling 40 units a day with a 14-day lead time and 93 units of safety stock means reordering when stock hits 653 units.
Should I count inventory on order?
Yes — trigger on "inventory position" (on hand + on order), not just what is on the shelf. Otherwise you double-order every time a purchase order is already in flight.
What happens if I ignore safety stock?
You will be in a stockout roughly half the time an order cycle runs long or demand runs high — lead-time demand only covers the average case. The safety stock term is what buys you a real service level.
How often should I recalculate reorder points?
Whenever demand or lead times shift meaningfully — at minimum each season, and immediately after supplier changes. Stale reorder points quietly become either stockout generators or dead-stock factories.