Sell-Through Rate
Units sold divided by average units on hand. The core efficiency number.
Definition
Sell-through rate is the number of units you sold over a period divided by the average number of units you had available during that period, expressed as a ratio or percentage. Amazon's FBA dashboard reports it as units sold over the trailing 90 days divided by your average available inventory.
Why sell-through rate matters for an FBA seller
Sell-through rate tells you how hard your inventory dollars are working. A high rate means product moves before it racks up storage fees. A low rate means cash is sitting in a warehouse aging toward surcharges.
It is also a direct input into your IPI. Amazon explicitly rewards a healthy sell-through, so a SKU that turns slowly does double damage: it ties up capital and it drags down the score that governs your storage limits.
How sell-through rate connects to your restock decisions
Sell-through is the signal that tells you how much to reorder and how often. A SKU with strong, steady sell-through can support deeper buys with confidence. A SKU with weak sell-through should get smaller, more frequent orders so you are not committing cash to product that crawls.
Track it by SKU, not as a blended account number. The account average hides the slow movers that are quietly costing you. Pair sell-through with days of supply and lead time so the reorder quantity reflects both how fast it sells and how long it takes to arrive.
Related terms
Track sell-through on every SKU
Inventory Hero shows sell-through per product against your real Amazon data, so you spot the slow movers piling up storage fees before they hurt your IPI.
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