📦 Safety Stock Calculator
Calculate safety stock and reorder point to prevent stockouts at your desired service level.
Demand & Lead Time
Peak demand day
Worst-case supplier delay
Safety Stock Methods
Basic Method: Safety Stock = (Max Daily Sales โ Avg Daily Sales) ร Max Lead Time. Simple and conservative โ useful when you lack historical demand data.
Statistical Method: Safety Stock = Z ร ฯdemand ร โ(Avg Lead Time). This accounts for demand variability more precisely. The Z-score corresponds to your chosen service level.
Reorder Point = (Avg Daily Sales ร Avg Lead Time) + Safety Stock. This is the inventory level at which you place a new order so stock arrives before you run out.
Service Level vs. Inventory Cost Trade-off
| Service Level | Z-Score | Stockout Risk | Inventory Impact |
|---|---|---|---|
| 90% | 1.28 | 10% of cycles | Lowest buffer |
| 95% | 1.65 | 5% of cycles | Moderate buffer |
| 99% | 2.33 | 1% of cycles | Highest buffer |