🔍 Overview
Amazon inventory metrics like Inventory Performance Index (IPI), Sell-Through Rate (STR), and Sell-Through directly affect how much inventory you can store, how fast it moves, and how profitable your FBA business is.
This guide explains how these metrics work and how to use them to avoid restrictions and scale with confidence.
👥 Who This Is For
This guide is useful for:
🆕 New Amazon sellers trying to understand inventory limits
📦 FBA sellers managing restocks and aging inventory
📈 Growing brands planning for scale or Q4 demand
🧠 Advanced sellers optimizing cash flow and operational efficiency
🧩 Key Concepts You Need to Know
Before taking action, understand how Amazon evaluates inventory health.
📊 Inventory Performance Index (IPI)
A composite score Amazon uses to measure how efficiently you manage FBA inventory. It impacts storage and restock limits.🔄 Sell-Through Rate (STR)
How quickly inventory sells compared to the average inventory on hand.⚠️ Excess Inventory
Units Amazon predicts will not sell in a reasonable timeframe.🏢 FBA Storage Limits
The maximum inventory Amazon allows you to store, influenced by your IPI score.
📍 All metrics are found in Seller Central → Inventory → Inventory Performance.
🛠️ Step-by-Step Guide: How to Manage IPI, STR, and Sell-Through
1️⃣ Review Your Inventory Performance Dashboard Weekly
Navigate to Seller Central → Inventory → Inventory Performance
Monitor:
IPI score
Sell-Through
Excess inventory
Stranded inventory
✅ Best Practice: Track trends, not single-week changes
❌ Common Pitfall: Overreacting to short-term dips
💡 Pro Tip: Add a weekly calendar reminder to review inventory health.
2️⃣ Improve Sell-Through by Reducing Overstock
Identify SKUs with:
Low sales velocity
High days of supply
Take action:
Adjust pricing
Add coupons
Pause restocks on slow movers
✅ Best Practice: Match inventory levels to real demand
❌ Common Pitfall: Restocking based on hope, not data
💡 Pro Tip: Aim for a Sell-Through Rate above 1.0 for most products.
3️⃣ Remove or Liquidate Excess Inventory Early
Review Excess Inventory recommendations
Choose:
🚚 Removal orders
♻️ Liquidation
🔖 Aggressive promotions
✅ Best Practice: Act before long-term storage fees hit
❌ Common Pitfall: Waiting for sales that never come
💡 Pro Tip: Small losses now often prevent bigger losses later.
4️⃣ Fix Stranded Inventory Immediately
Check the Stranded Inventory report
Common causes:
Listing errors
Suppressed ASINs
Missing pricing
✅ Best Practice: Resolve issues within days
❌ Common Pitfall: Ignoring “small” stranded quantities
💡 Pro Tip: Even a few stranded units can hurt your IPI.
5️⃣ Align Restocking with Actual Sales Velocity
Base restocks on:
30–60 day sales averages
Seasonality trends
Avoid bulk shipments without proven demand
✅ Best Practice: Smaller, frequent shipments reduce risk
❌ Common Pitfall: Over-shipping to save on freight
💡 Pro Tip: Amazon rewards consistency more than volume.
🧪 Real-World Examples
📦 Example 1: Small Private Label Seller
Seller Type: Beginner FBA seller (2 SKUs)
Problem: IPI dropped due to slow-moving inventory
Action: Paused restocks, ran coupons, removed excess units
Result: IPI recovered in 6 weeks
🏷️ Example 2: Mid-Size Brand Scaling Catalog
Seller Type: 7-figure brand with 30+ ASINs
Problem: Storage limits blocking launches
Action: Reduced depth on low-velocity SKUs
Result: Improved sell-through and restock capacity
🚫 Common Mistakes to Avoid
❌ Chasing the IPI Score Instead of the Drivers
Sellers fixate on the number, not the causes.
✅ Fix inventory health—the score follows.❌ Over-Restocking Past Winners
Yesterday’s demand ≠ today’s demand.
✅ Use recent sales data, not historical peaks.❌ Waiting Until Amazon Restricts You
Action often comes too late.
✅ Review inventory metrics weekly.
🎯 Expected Results
By applying these practices, sellers can expect:
📈 More stable IPI scores
🚫 Fewer storage and restock restrictions
💰 Lower storage and removal fees
🔄 Faster inventory turnover
📦 More predictable scaling capacity
❓ FAQs
What is a good IPI score?
✅ Generally 400+, with higher scores offering more flexibility.
How often is IPI updated?
🔁 Typically recalculated weekly.
Do ads improve sell-through?
📢 They can help, but won’t fix poor inventory planning.
Does FBM inventory affect IPI?
🚚 No. IPI applies only to FBA inventory.
Is removing inventory bad?
❌ No. Strategic removals often reduce long-term losses.
Use this checklist once per week to review your FBA inventory health, protect your IPI score, and catch issues like excess or stranded inventory before they affect storage limits or fees.