Plain-English difference
Safety stock answers how much buffer you want. Reorder point answers when to place the next order.
Search intent: Users want to understand how reorder point and safety stock differ before calculating inventory needs.
Reorder Point vs Safety Stock
Safety stock is the buffer inventory held for uncertainty. Reorder point is the inventory position where you should place a replenishment order. They work together because reorder point includes expected demand during lead time plus safety stock.
Single-SKU calculator
How the calculation works
Formula comparison
Safety stock is calculated from uncertainty in demand and lead time. Reorder point = average daily demand x lead time days + safety stock.
When reorder point changes
Reorder point changes when average daily sales, supplier lead time, or safety stock changes. A faster sales rate or longer lead time raises the reorder point.
Input fields explained
| Field | Why it matters |
|---|---|
| average_daily_sales | Raises or lowers expected demand during lead time. |
| lead_time_days | Controls how many days of demand must be covered before replenishment arrives. |
| lead_time_variability_days | Can increase safety stock when suppliers are inconsistent. |
| desired_service_level | Higher service levels increase the buffer. |
| current_stock and incoming_stock | Do not define the reorder point, but decide whether the SKU is below it. |
Worked example
If average demand is 5 units/day and lead time is 14 days, expected lead-time demand is 70 units. If safety stock is 25 units, reorder point is 95 units. If inventory position is 80 units, the SKU is below reorder point.
Common mistakes
- Using safety stock and reorder point as the same number.
- Increasing reorder point without checking whether demand or lead time actually changed.
- Ignoring supplier delays when calculating safety stock.
- Comparing reorder point to current stock only when incoming stock is already on order.
When not to rely on the result
Do not rely only on these formulas for new products, seasonal products, promotion periods, or SKUs with long stockout history. The inputs may not represent normal demand.
FAQ
Is safety stock part of reorder point?
Yes. Reorder point includes expected demand during lead time plus safety stock.
When should I increase safety stock?
Increase it when demand is more variable, suppliers are less reliable, or stockouts are more costly.
Can reorder point go down?
Yes. It can go down when daily demand falls, supplier lead time improves, or you choose a lower safety stock buffer.