A deterministic reorder trigger using average demand and explicit safety stock. It does not calculate a probabilistic service level or guarantee against stockouts.
Calculation details
Planning estimate only. Platform fees, taxes, payment costs, and policies can change; verify current terms before pricing.
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What does this calculator estimate?
Use this reorder point calculator to determine when to reorder inventory. Enter average daily sales, lead time, safety stock, and current stock. It calculates lead time demand as daily sales times lead time, adds safety stock, and compares the result with current stock to show whether it is time to reorder.
How this calculator works
Formula
Lead-time demand = average daily sales × supplier lead-time days. Reorder point = lead-time demand + entered safety stock. The order-now signal activates when current stock is at or below that point.
Worked example
10 units per day, seven lead-time days, and 20 safety-stock units produce a 90-unit reorder point. At 80 units on hand, the trigger is active.
Assumptions to verify
- Average daily demand and supplier lead time remain constant.
- Safety stock is entered explicitly rather than inferred from a service level.
- Open purchase orders, seasonality, minimum order quantities, spoilage, backorders, and multi-location inventory are excluded.
Frequently asked questions
What is the reorder point formula?
Reorder point equals average daily sales multiplied by lead time days, plus safety stock units.
When should I reorder inventory?
Reorder when current stock is at or below the calculated reorder point.
What is lead time demand?
Lead time demand is the inventory expected to sell during replenishment lead time: average daily sales times lead time days.
Cite this tool
BoringToolsKit. “Inventory Reorder Point Calculator.” boringtoolskit.com/inventory-reorder-point-calculator/ (reviewed July 2026). Free to reference in articles, syllabi, and answer posts with a link.
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