How many days of stock do I have left on Amazon?
Days of cover is sellable units divided by the daily sales rate of that product — not a fixed threshold. A product selling two a day and one selling two hundred cannot share a reorder point. The reorder date is days of cover minus your lead time: if the route takes 42 days and you have 60 days of stock, you have 18 days to decide, not 60. Units already in transit count; units that are stranded do not.
Why “below 30 days” means different things
A fixed threshold treats a product that sells two a day and one that sells two hundred as the same case. One of them has a month to react; the other needed to order last week. The threshold should come from the product, not from the dashboard.
The reorder date, worked through
| Input | Value |
|---|---|
| Sellable units | 1,200 |
| Daily sales rate | 20 |
| Days of cover | 60 |
| Lead time (sea) | 42 days |
| Decision window | 18 days |
Reading “60 days of stock” as comfortable is the mistake. The usable number is 18.
Excess stock is the quiet cost
Low stock announces itself: the listing goes out of stock and sales stop. Dead stock announces nothing — it just pays storage, ages toward long-term storage fees, and holds capital that could have funded the product that is selling.
Both deserve a flag. A stock screen that only warns about shortages is doing half the job.
Checklist
- Is days of cover computed from each product’s own sales rate?
- Is lead time included in the reorder point?
- Are in-transit units counted, and stranded units excluded?
- Is dead stock flagged as loudly as low stock?
Frequently asked questions
How do I calculate days of cover?
Divide sellable units by the product’s own average daily sales. Include units in transit, exclude stranded and unfulfillable units.
When should I reorder?
When days of cover drops to the lead time of your normal route plus a safety margin. The fast route is for when planning failed, not for the plan.
Is excess stock a problem?
Yes. It pays storage every month, risks long-term storage fees, and ties up money that could have bought the product that is selling.