> ## Documentation Index > Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Sell-Through Rate (FBA), Amazon Seller Central > Sell-Through Rate (FBA) for Amazon Seller Central. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it. **Card class:** [Standard](/nerve-centre/overview#card-classes-explained) • **Category:** [Inventory Forecasting](/nerve-centre/connectors#connectors-by-type) ## At a glance > How fast your FBA inventory turns. Sell-through compares units sold to the average units held over the period, so it tells you whether stock is moving at a healthy clip or sitting in Amazon's warehouses racking up storage fees. It is the metric behind Amazon's own Inventory Performance Index (IPI): low sell-through means overstock, capital tied up, and long-term storage exposure; very high sell-through means you are flirting with stockouts. The card flags SKUs turning at less than half the category norm. | | | | --------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **What it measures** | Units sold over the period divided by the average FBA units on hand over the same period, a turnover ratio. Higher means inventory is moving quickly; lower means it is sitting. | | **Why it matters** | Slow sell-through is the root of overstock costs: storage fees, long-term storage surcharges, stranded capital, and a weak IPI that can trigger storage limits. Fast sell-through risks the opposite, stocking out and losing rank. | | **Link to IPI** | Sell-through and excess inventory are core inputs to Amazon's Inventory Performance Index. A persistently low sell-through drags IPI down, which can cap how much you are allowed to send into FBA. | | **FBA-specific** | This is an FBA card because FBA is where the storage clock runs. FBM stock sits in your own warehouse on your own cost basis, so the Amazon-fee consequence does not apply the same way. | | **Benchmark, not absolute** | "Good" sell-through is category-dependent. The alert is relative: a SKU below half the category median is turning too slowly regardless of the absolute number. | | **Action when low** | Reduce inbound, run a promotion or coupon, lower price, bundle, or create a removal order before long-term storage fees bite. | | **Time window** | `90D` (the selected period) | | **Alert trigger** | `<0.5x category median`, turning at under half the category norm | | **Roles** | owner, operations, finance | ## 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 toys-and-games FBA seller reviewing 90D sell-through on 01 May 26. Assume the category median sell-through for the period is about 1.5x. Figures are illustrative. | SKU | Units sold (90D) | Avg units on hand | Sell-through | vs category median (1.5x) | Read | | ------------ | ---------------- | ----------------- | ------------ | ------------------------- | ------------------------------------- | | Hot seller A | 5,400 | 1,800 | 3.0x | 2.0x median | turning fast, watch for stockout | | Steady B | 2,700 | 1,800 | 1.5x | at median | healthy | | Slow C | 600 | 1,500 | 0.4x | 0.27x median | alert: overstocked | | Dead D | 90 | 1,200 | 0.075x | 0.05x median | alert: severe overstock, plan removal | ```text theme={null} Category median ≈ 1.5x ; alert threshold = below 0.5 × 1.5 = 0.75x Slow C = 0.4x → below 0.75x, flagged. ~3 months of stock barely moving. Dead D = 0.075x → far below; this is capital frozen and a storage-fee liability. Plan a removal/markdown. Hot A = 3.0x → excellent turnover, but watch cover so it does not stock out. ``` Four things to notice: 1. **Low sell-through is money sitting still.** Dead D turned only 90 units against 1,200 average on hand over a full quarter. That is frozen capital and a growing storage bill. The fix is markdown, bundle, or removal, not "wait and see", because long-term storage surcharges escalate the longer it sits. See [ASINs Approaching Long-Term Storage](/nerve-centre/kpi-cards/amazon-seller/asins-approaching-long-term-storage). 2. **The benchmark is relative, not absolute.** A 0.4x sell-through might be fine in a slow-moving category and a disaster in a fast one. The alert fires on under half the category median, which is why Slow C is flagged at 0.4x against a 1.5x norm but would not be in a category that naturally turns at 0.5x. 3. **Very high sell-through is a different risk.** Hot A's 3.0x is great for cash and IPI, but it is the SKU most likely to stock out. Pair high sell-through with [Days of Cover (avg)](/nerve-centre/kpi-cards/amazon-seller/days-of-cover-avg) and [Replenishment Recommendations](/nerve-centre/kpi-cards/amazon-seller/replenishment-recommendations) so a fast turner does not run dry. 4. **This feeds your IPI and your storage limits.** Persistent low sell-through across the catalogue drags Amazon's Inventory Performance Index down, which can restrict how much you are allowed to send in. Sell-through is not just a margin metric, it gates your ability to operate FBA at scale. ## Sibling cards merchants should reference together Sell-through is the turnover read. These cover the cost of getting it wrong in either direction: | Card | Why pair it with Sell-Through Rate (FBA) | | ---------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- | | [Days of Cover (avg)](/nerve-centre/kpi-cards/amazon-seller/days-of-cover-avg) | The flip side. High sell-through plus low cover means stockout risk; low sell-through plus high cover means overstock. | | [Stranded Inventory Value](/nerve-centre/kpi-cards/amazon-seller/stranded-inventory-value) | Where chronically low sell-through ends up, capital stuck in stock that will not move. | | [ASINs Approaching Long-Term Storage](/nerve-centre/kpi-cards/amazon-seller/asins-approaching-long-term-storage) | The escalating fee consequence of slow sell-through; act before stock ages into the surcharge. | | [FBA Storage Fees](/nerve-centre/kpi-cards/amazon-seller/fba-storage-fees) | The running cost of holding slow-moving stock. Low sell-through inflates this. | | [Replenishment Recommendations](/nerve-centre/kpi-cards/amazon-seller/replenishment-recommendations) | Uses velocity to right-size reorders so you do not recreate the overstock. | | [ASINs Stocking Out \<7 Days](/nerve-centre/kpi-cards/amazon-seller/asins-stocking-out-7-days) | The high-sell-through hazard, fast turners running out. | ## Reconciling against Amazon Seller Central **Where to look in Seller Central:** The closest Amazon-native views are: > **Inventory → Inventory Planning → Inventory Performance Dashboard** (IPI, sell-through, excess inventory), and > **Reports → Fulfilment → Inventory** reports for units on hand and units sold per SKU. Amazon's Inventory Performance Dashboard publishes a sell-through figure and the IPI it feeds. Expect this card's per-SKU sell-through to track Amazon's account-level figure in spirit, though the exact ratio depends on the averaging method and window each tool uses. **Timing, settlement, and reporting-lag table:** | Topic | Detail | | ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Average-inventory method** | Sell-through depends on how average units on hand is computed (start/end average vs daily average over the window). Different methods give slightly different ratios; Amazon's IPI uses its own method. | | **Window length** | The ratio scales with the window. A 90D sell-through is not directly comparable to a 30D one. Compare like windows. | | **Available vs total** | Whether reserved and unfulfillable units are included in "on hand" affects the denominator. Stranded units in the denominator depress the ratio. | | **Reporting lag** | Inventory snapshots and sales settle on slightly different schedules, so the freshest ratio can move as the latest data finalises. | **Why our number may legitimately differ from Seller Central:** | Reason | Direction | Why | | --------------------------------- | ------------------- | ---------------------------------------------------------------------------------------------------- | | **Averaging method** | Either direction | Start/end vs daily-average inventory produces different denominators and therefore different ratios. | | **Window mismatch** | Scales with window | A 90D ratio differs from Amazon's default IPI window; align periods before comparing. | | **Stranded units in denominator** | Ours may read lower | Including unfulfillable stock in on-hand depresses sell-through; excluding it raises it. | | **Category-median basis** | Judgement | The "category median" benchmark is an estimate of the norm, not an official Amazon figure. | **Cross-connector reconciliation against other connectors the same seller may run:** | Card | Expected relationship | What causes legitimate divergence | | ------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- | | [`amazon.days_of_cover_avg`](/nerve-centre/kpi-cards/amazon-seller/days-of-cover-avg) | **Inverse-ish relationship.** High sell-through tends to mean low days of cover and vice versa, both built from velocity and on-hand stock. | They diverge when inventory is lumpy (a big inbound shipment) because cover is forward-looking while sell-through is backward-looking. | | [`shopify` inventory turnover](/nerve-centre/kpi-cards/shopify/total-revenue) | **Same concept, different cost basis.** DTC stock turnover matters for cash but has no Amazon storage-fee or IPI consequence. | If stock is pooled across channels, reconcile total on-hand; if separate, the two are independent. | ## Known limitations / merchant FAQs **What is a good sell-through rate?** There is no universal number, it is category-dependent. A fast-moving consumable turns far quicker than a niche durable. That is why the alert is relative (below half the category median) rather than a fixed threshold. Read your SKUs against their category, not against each other. **Why is this FBA-only?** Because FBA is where Amazon's storage clock and Inventory Performance Index apply. Slow FBA stock costs you storage fees, long-term surcharges, and IPI points that can cap your inbound. FBM stock sits on your own cost basis without those specific Amazon consequences, so the metric means something different there. **How does sell-through affect my IPI and storage limits?** Sell-through and excess inventory are core IPI inputs. A persistently low sell-through drags IPI down, and a low IPI can restrict how much inventory Amazon lets you send into FBA. So slow turnover does not just cost storage fees, it can throttle your whole FBA operation. **My sell-through is very high, isn't that good?** Mostly, it means great turnover and healthy cash. But it is also the SKU most likely to stock out. Pair high sell-through with [Days of Cover (avg)](/nerve-centre/kpi-cards/amazon-seller/days-of-cover-avg) so a fast turner does not run dry and surrender rank and Buy Box. **Why doesn't my number match Amazon's dashboard exactly?** Different averaging methods and window lengths. Amazon's IPI uses its own calculation of average inventory and its own window. Both are valid; align the period and treat the card's per-SKU view as the actionable, more granular read. **What do I do about a chronically low sell-through SKU?** Stop sending more in, then move the existing stock: a coupon or price cut, a bundle, advertising, or, if it truly will not sell, a removal order before long-term storage fees escalate. Check [ASINs Approaching Long-Term Storage](/nerve-centre/kpi-cards/amazon-seller/asins-approaching-long-term-storage) for the deadline. *** ### Tracked live in Vortex IQ Nerve Centre *Sell-Through Rate (FBA)* is one of hundreds of KPI pulses Vortex IQ tracks across Amazon Seller Central and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. [Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.