IPI Score vs. Sell-Through Rate: How They Relate

Sell-through rate is one of the most heavily weighted factors in your Amazon IPI score. Amazon calculates sell-through rate as: units sold in the last 90 days divided by your average number of units on hand in the last 90 days. A sell-through rate of 1.0 means you sold exactly as many units as you had on hand on average — essentially, your inventory turned over completely in 90 days. A rate above 1.0 means you had stockouts (sold more than you had), which is not ideal. A rate below 0.5 means you are selling through less than half your inventory in 90 days, which typically contributes to a lower IPI. Amazon categorizes sell-through rate into performance tiers, with rates above approximately 0.8 considered "good" and below 0.5 considered "poor." To improve your sell-through rate: focus on your highest-inventory, lowest-velocity ASINs. A 15% price cut on a product selling 2 units per month that you have 200 units of will dramatically improve that product's sell-through rate and have an outsized impact on your IPI. Sell-through rate responds to price changes, advertising changes, and listing improvements within the 90-day rolling window, so improvements you make today start showing in your IPI within a few weeks.