At a glance
How many days your current inventory will last at the recent rate of sale. For each SKU, the card divides available units by the trailing daily sales rate to get days of cover, then averages across the catalogue (with the top sellers weighted by attention). Too few days means a stockout is coming, which kills Buy Box and burns ad spend; too many days means cash is trapped in slow stock and FBA storage fees are mounting. The sweet spot leaves enough runway to reorder and replenish before you run dry.
Calculation
Calculated automatically from your Amazon Seller Central data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A pet-supplies brand on Amazon UK, FBA, snapshot 30 Apr 26, reorder lead time roughly 21 days. All numbers illustrative.- The average hides two emergencies. The top-20 average of ~19 days looks borderline, but dog chews (7 days) and the grooming brush (8 days) are already below lead time. By the time stock arrives, both will have stocked out. The average is reassuring; the per-SKU view is not.
- 19 days breaches the alert. With the top-20 average under the
<14 days on top-20 SKUsline being approached and individual SKUs already under it, Vortex IQ Nerve Centre flags the at-risk SKUs. The right response is per-SKU expediting, not a blanket reorder. - The slow feeder bowl is the opposite problem. 200 days of cover means cash is trapped and FBA long-term storage fees are looming. Pair with ASINs Approaching Long-Term Storage and consider a markdown or removal.
- Lead time, not a fixed number, sets your floor. A 14-day cover is fine for a SKU with a 7-day lead time and dangerous for one with a 21-day lead time. Always read cover against the specific SKU’s replenishment lead time.
- A promo distorts the rate. If the dog chews just came off a 7-day deal, the trailing daily rate of 60 is inflated and real cover is better than it looks. Check whether the recent rate reflects normal demand before reacting.
Sibling cards merchants should reference together
Cover is a leading indicator; pair it with the consequences:Reconciling against Amazon Seller Central
Where to look in Amazon Seller Central:Seller Central → Inventory → Inventory Planning (FBA) shows days of supply and a sell-through view per SKU. The Restock Inventory tool surfaces Amazon’s own days-of-supply estimate and recommended reorder quantities, which is the closest native equivalent.For raw availability, Seller Central → Inventory → Manage FBA Inventory shows available, reserved, inbound, and unfulfillable units per SKU. Timing, settlement, and reporting-lag table:
Why our number may legitimately differ from the Restock tool:
Cross-connector reconciliation against other connectors the same seller may run:
Known limitations / merchant FAQs
The average looks fine but I still stocked out. Why? Because an average hides the SKUs that matter. A healthy catalogue average can sit on top of several top-revenue SKUs about to run dry. Always drill into the per-SKU view and read cover against each SKU’s reorder lead time. Why is my cover lower than my total stock suggests? The card uses sellable (available) units, which exclude reserved, inbound, and unfulfillable inventory. Units on a boat to the fulfilment centre do not count toward cover until they are received and sellable. A SKU just came off a promotion and its cover collapsed. Is it real? Often not. The trailing daily sales rate is inflated by the promo spike, so cover reads artificially low. Wait for demand to normalise, or check whether the recent rate reflects steady-state demand before expediting a reorder. What is a safe number of days of cover? There is no universal answer; it depends on your reorder lead time. Cover should comfortably exceed lead time plus a safety buffer. A 14-day cover is fine with a 7-day lead time and dangerous with a 21-day lead time. Can I change the alert threshold? Yes. The<14 days on top-20 SKUs default is configurable per profile in the Alert Rules tab. Set it to your typical reorder lead time plus a buffer so the alert fires while there is still time to act.