This reorder calculator estimates a physical-product reorder point using average daily demand, supplier lead time, and safety stock. It identifies the inventory position at which a replenishment order should be triggered so expected lead-time demand is covered.
The model is most useful for relatively stable demand and lead times. Seasonal spikes, promotions, minimum order quantities, supplier closures, and inbound variability should be handled through adjusted inputs or a more detailed inventory plan.
1. Enter average daily demand. Use values from the same product, SKU group, and reporting period.
2. Enter lead time. Use values from the same product, SKU group, and reporting period.
3. Enter safety stock. Use values from the same product, SKU group, and reporting period.
4. Enter current inventory position. Use values from the same product, SKU group, and reporting period.
5. Review the result. The calculator updates automatically as inputs change. Use Reset to restore the example values.
The displayed value summarizes estimated reorder point using the inputs entered above.
Use consistent units and matching reporting periods. Results are estimates for planning and review.
Given: 18 units/day, 21 days of lead time, and 120 safety units.
Calculation: 18 × 21 + 120 = 498 units.
Result: Trigger replenishment when inventory position reaches 498 units.
On-hand stock plus confirmed inbound units minus committed or backordered units.
Base it on demand and lead-time uncertainty or your desired service level.
Use the same calendar basis as your daily demand. Business-day lead time requires business-day demand.
Yes, if lead time is converted to weeks so units remain consistent.
Use a forecast for the upcoming lead-time window rather than a long-run average.