{"id":11705,"date":"2026-03-11T14:48:15","date_gmt":"2026-03-11T14:48:15","guid":{"rendered":"https:\/\/www.aihello.com\/resources\/?p=11705---38ad1b6b-59d1-4a87-ba6a-8042e76e5a7d"},"modified":"2026-03-19T03:08:44","modified_gmt":"2026-03-19T03:08:44","slug":"amazon-inventory-management","status":"publish","type":"post","link":"https:\/\/www.aihello.com\/resources\/blog\/amazon-inventory-management\/","title":{"rendered":"Amazon Inventory Management: A Practical Guide for FBA Sellers"},"content":{"rendered":"

Amazon<\/a> inventory management directly affects your sales<\/a>, ad performance, storage fees, and even your organic ranking. If you run out of stock, your listing can lose visibility and the Buy Box. If you overstock, Amazon charges monthly and aged inventory fees that eat into your profit.<\/p>

More than 82% of sellers use FBA, yet many lose money<\/a> because they don\u2019t manage their stock properly. You\u2019ve probably experienced it yourself: having capital stuck in slow-moving inventory<\/a> or missing out on sales because a top SKU ran out. <\/p>

This guide shows you how to<\/a> forecast accurately, reorder on time, and clean up excess inventory. Ready to protect your margins and grow your business with less stress? Dive right in!<\/p>

Key Inventory Metrics Every Amazon Seller Should Track<\/strong><\/h2>

To manage your inventory<\/a> well, you can\u2019t just guess or reorder only when your stock is running low. You need to track the right metrics because they tell you exactly when to restock, how much to send in, and which SKUs are hurting your cash flow.<\/p>

1. Inventory Performance Index (IPI Score)<\/strong><\/h3>
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This is Amazon\u2019s scorecard for how well you manage inventory. It\u2019s updated weekly and calculated based on four factors: excess inventory, sell-through rate, stranded inventory, and in-stock rate on popular ASINs.<\/p>

If your IPI score falls below 400, Amazon may limit how much inventory you can send in. That means even if your product is selling well, you won\u2019t be able to restock past a certain number units.<\/p>

You can find your IPI score and detailed breakdowns in the FBA Inventory Dashboard.<\/p>

2. Sell-Through Rate (STR)<\/strong><\/h3>
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This tells you how quickly your products are selling relative to how much stock you have in FBA.<\/p>

STR = Total units sold over the last 90 days \u00f7 average units stored over 90 days.<\/p>

If you sold 300 units in 90 days and had an average of 100 units stored, your STR is 3.0. That\u2019s good. Amazon recommends keeping it above 2.0. If your STR is too low, you may get flagged for excess inventory, which lowers your IPI score.<\/p>

You can find your STR on the FBA Inventory Dashboard, but you can also calculate it manually for individual SKUs to spot problem areas.<\/p>

3. Days of Supply<\/strong><\/h3>
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This shows how long your current FBA inventory will last if your daily sales stay the same.<\/p>

Days of Supply = Current FBA units \u00f7 average daily sales.<\/p>

For example, if you have 600 units in stock and you’re selling 20 per day, you have 30 days of supply. For most SKUs, the sweet spot is 30 to 60 days. Less than that, you risk going out of stock. More than that, you risk paying more storage fees than necessary.<\/p>

Amazon\u2019s Restock Inventory tab gives you a rough projection, but tracking this manually for your top SKUs can help you make smarter restock decisions.<\/p>

4. Stranded Inventory<\/strong><\/h3>
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Stranded inventory is stock sitting in FBA with no active listing. That means customers can’t buy it, but you\u2019re still paying storage fees. <\/p>

Your inventory could be stranded due to a listing error, price violation, or brand<\/a> gating, and leaving even a few ASINs stranded for weeks can silently chip away at your margins.<\/p>

5. Excess and Aged Inventory<\/strong><\/h3>
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Amazon flags inventory as \u201cexcess\u201d if it isn\u2019t projected to sell in the next 90 days. Once it hits 181 days, it becomes \u201caged\u201d and attracts higher monthly storage fees. After 271 days, the fees increase even more.<\/p>

When you consistently track these metrics, making inventory decisions becomes a lot easier. You\u2019ll know which SKUs to reorder, which ones to slow down, and when to run a promotion to clear space.<\/p>

Common Amazon Inventory Challenges and How to Fix Them<\/strong><\/h2>

Every Amazon seller<\/a>, no matter how experienced, runs into inventory issues. It\u2019s part of the business. What matters is how early you catch them and how quickly you act.<\/p>

Here are five of the most common problems, and what to do when they show up:<\/p>

1. Running Out of Stock Faster Than Expected<\/strong><\/h3>

Sometimes, you order enough units, but sales spike due to a keyword<\/a> ranking boost or a successful ad campaign.<\/p>

If you run out completely, Amazon will bury your ranking and restrict how much you can send in later. Here\u2019s how to fix it:<\/p>