What Is Amazon IPI Score? A Complete Explanation

The Amazon Inventory Performance Index (IPI) is a score from 0 to 1000 that Amazon uses to measure how effectively FBA sellers manage their inventory. As of 2024, Amazon uses the IPI score to determine how much FBA storage space a seller is allocated. Sellers with IPI scores below Amazon's threshold (historically around 400-450, though Amazon adjusts this periodically) face storage limits that restrict how much inventory they can have at Amazon's fulfillment centers at any given time. The IPI score considers four main factors: excess inventory percentage (what portion of your inventory is categorized as excess based on supply relative to recent sales), sell-through rate (how quickly you are selling through your inventory over the last 90 days), stranded inventory percentage (how much of your inventory has no active offer), and in-stock rate (how often your fastest-selling products are in stock). Amazon weights these factors, with sell-through rate and excess inventory typically having the greatest influence. The score is updated weekly and visible in Seller Central under Inventory > Inventory Performance.