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Restock calculator
Enter current stock, average daily sales, supplier lead time, the safety buffer you want and any units already on the way. The calculator returns days of cover, the reorder point and a suggested order for the review period.
Cover, reorder point and the order quantity
Days of cover is stock on hand divided by average daily sales. It answers how long the current stock lasts if demand stays flat. The reorder point is the stock level that triggers a new order: daily sales multiplied by lead time plus the safety buffer.
The suggested order covers the review period plus the lead time and the buffer, net of stock on hand and units already in transit. It is a planning number, not a purchase order; round it to the supplier's carton or MOQ.
Where the model breaks
Demand is not flat. A launch, a promotion or a seasonal peak can double daily sales, and a supplier delay can add a week. Use a demand range and a lead-time range for important SKUs, and treat the output as the midpoint.
The cash line matters as much as the units. The inventory value shows how much cash the current stock represents; the suggested order adds more. Compare the order with the cash-flow model before committing.
Inventory and fulfilment reference
Every entry links to its full reference page. The search box above filters this list.
Frequently asked questions
Should I use average or recent daily sales?
Use a recent window that reflects the current demand, and test a higher number for a promotion or a peak. A long average can hide a recent trend.
What safety buffer should I use?
It depends on demand variability and lead-time reliability. A longer or less reliable lead time needs a larger buffer.
Does the calculator include units in transit?
Yes, in the stockout and suggested-order outputs. Days of cover shows on-hand stock separately.
How does this relate to the low-inventory-level fee?
The fee uses historical days of supply. This calculator gives a planning view; compare the result with the marketplace threshold and fee schedule.
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