Buffer inventory (safety stock) and reorder point calculator
One item
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Formula: safety stock = Z × √(lead time × σ_demand² + demand² × σ_leadtime²). With a fixed lead time it reduces to Z × σ_demand × √lead time. Reorder point = average demand × lead time + safety stock.
Your whole catalog at once
Paste the history exported from your ERP, one row per item: SKU, lead time (in periods) and demand for each period (days, weeks or months, always the same). Comma, semicolon or tab separated.
| SKU | Avg demand/period | Std dev | Lead time (periods) | Safety stock | Reorder point |
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Put it in your system, not a spreadsheet
A one-off calculation goes stale as soon as sales or a supplier change. What helps is having it recalculated automatically:
- In Business Central: the results go into the standard item or stockkeeping-unit fields (safety stock quantity, reorder point, reorder quantity, lead time calculation, reordering policy) and the planning worksheet proposes the purchases. With an extension, they are recalculated every month from your actual sales.
- In another ERP: if it has an API or file import, we calculate from your history and load the values, with periodic recalculation too.
- With alerts: items below their reorder point, suppliers running late and stock that has stopped moving.
More context: buffer inventory explained, with worked examples, dead stock and carrying cost.
Want it calculated and kept current in your system?
Send us your sales export in the free assessment and we will show you the result for your SKUs. If we implement it, each part is invoiced only after you accept it.