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
See it applied in Inventory Hero
Inventory Hero turns these inputs into restock recommendations against your real Amazon SKUs.
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