Inventory Holding Cost and Tariff Analysis Tool

Choose an input method:

Manual Entry Upload CSV File (all the imput calcs done for you)

Average Daily Demand (units)

Demand Variability (units)

Average Lead Time (days)

Lead Time Variability (days)

Cost per Unit ($)

Additional Tariff Cost (0%)

Service Level 95% (higher value means less stock outs)

Safety Stock: 0.00 units

Holding Cost: $0.00

D (Average Daily Demand): Average number of units sold daily. If your store sells 75 units daily on average, input 75.
L (Average Lead Time in Days): Number of days between placing an order and receiving goods. For example, a supplier who delivers in 7 days means L = 7.
σ_D (Demand Standard Deviation): Measures variability in daily demand. High variation = more uncertainty = higher safety stock.
σ_L (Lead Time Standard Deviation): Indicates how consistent your supplier is. More variance = greater need for buffer stock.
Z (Z-score): The service level you want to achieve. Higher Z = fewer stockouts, but higher inventory cost.
- 1.28 for 90% service level
- 1.65 for 95% service level
- 2.05 for 98% service level
- 2.33 for 99% service level

Formula:
Safety Stock = Z × sqrt((σ_D² × L) + (D² × σ_L²))
This ensures enough stock to meet demand despite supply or demand fluctuations.