Amazon FBA IPI: Budgeting Made Simple for Sellers

Amazon FBAIPI is a score that affects your storage limits and fees. This guide explains what it is, why it matters in 2026, and how to evaluate and improve it. You'll learn the key components, common pitfalls, and practical budgeting steps to keep your IPI healthy without overspending.

Why Amazon FBA IPI Matters in 2026

Amazon FBA inventory performance index (IPI) is a score that measures how efficiently you manage your FBA inventory. It directly determines your storage limits for standard-size and oversize items, and it influences your storage fees. In 2026, with tighter capacity and higher fees, maintaining a healthy IPI is critical for cost control and business continuity.

For cross-border e-commerce sellers, a low IPI can mean unexpected storage restrictions, forcing you to ship inventory to third-party warehouses or lose sales. A good IPI, on the other hand, allows you to plan your inventory with confidence, avoid overstocking fees, and keep your best-sellers in stock. This guide will walk you through the specifics of IPI, how to evaluate your score, and practical steps to improve it without overspending.

• IPI thresholds: 400 (below), 400-499 (fair), 500+ (good), 800+ (excellent)
• Storage limits are calculated quarterly, based on IPI and sales velocity
• High IPI can qualify you for unlimited storage on certain items, subject to Amazon policy

Key Components of Amazon FBA IPI

IPI is not a single metric but a composite of four factors: excess inventory, sell-through rate, stranded inventory, and in-stock rate. Each factor has a weight, though Amazon does not publish exact formulas. Understanding these components helps you target improvements effectively.

Excess inventory measures how much stock you have that covers more than 90 days of sales. Sell-through rate is the number of units sold divided by the average units in storage over a period. Stranded inventory includes items with listing errors that prevent sales. In-stock rate reflects how often your products are available for purchase when customers want them.

• Excess inventory: aim for <10% of your inventory that is excess (over 90 days of supply)
• Sell-through rate: target >70% for standard-size, >50% for oversize
• Stranded inventory: keep <2% of total units stranded
• In-stock rate: maintain >80% for your top-selling ASINs

How to Evaluate Your IPI: Criteria and Trade-offs

To evaluate your IPI, log into Seller Central and check the Inventory Performance dashboard. Your score updates daily, but the important thresholds are at the quarterly measurement dates (typically the last day of Q1, Q2, Q3, Q4). If you are above 400, you have unlimited storage for standard-size items; below 400, you get a capacity limit that can be increased if you pay for it.

Trade-offs exist between IPI and inventory levels. Keeping IPI high often means reducing excess inventory, which can lead to stockouts if demand spikes. Conversely, overstocking improves in-stock rate but hurts your excess inventory score. Balancing these requires accurate sales forecasting and a good understanding of your supply chain lead times.

Consider the cost of storage fees versus the cost of stockouts. Storage fees vary by size and time of year (peak fees from October-December). Stockouts can cost you Buy Box wins and customer trust. Use historical sales data and seasonality to set reorder points that minimize both risks.

• Check your IPI score weekly and set alerts for drops below 450
• Calculate your sell-through rate for each ASIN monthly
• Review stranded inventory reports and fix listing errors within 48 hours
• Use Amazon's Restock Inventory tool to estimate required quantities

Common Pitfalls When Managing IPI

A common mistake is ignoring IPI until you receive a storage limit notification. By then, you may have to remove inventory quickly, incurring removal fees. Another pitfall is overreacting to a low IPI by slashing inventory across the board, which can harm your sales velocity and in-stock rate.

Sellers often misunderstand sell-through rate. For example, a product with high sales but also high inventory may have a low sell-through rate if you have too much stock. Similarly, seasonal products can distort your score if you stock up too early. Also, don't forget about stranded inventory—it's easy to overlook listing errors, but they can drag down your IPI significantly.

Another issue is relying on Amazon's suggested restock quantities without adjusting for your own lead times. Amazon assumes a standard lead time, but if you ship from China, your actual lead time may be longer, leading to stockouts and a lower in-stock rate. Always adjust recommendations based on your real shipping times.

• Set a reminder for quarterly IPI measurement dates
• Don't delete inventory to improve IPI—remove it to a warehouse or create a removal order
• Use aged inventory reports to identify slow movers early
• Validate your shipping lead times and update them in your inventory plan

Practical Recommendations and Next Steps

To budget effectively for IPI, start by auditing your current inventory health. Use the Inventory Performance dashboard to see your score and the factors dragging it down. Then, create a 90-day plan to address the weakest areas: reduce excess, fix stranded items, improve sell-through, and maintain in-stock rates.

Implement a weekly inventory review process. Track your sell-through rate, excess inventory percentage, and stranded inventory count. Use tools like Inventory Lab or Sellerboard to automate reports. Also, consider using Amazon's FBA Inventory Age tool to see which items are aging and plan removal or promotion strategies.

Finally, set aside a budget for storage fees and potential removal costs. Storage fees are typically $0.87 per cubic foot for standard-size (January-September) and $2.40 per cubic foot for oversize; peak fees are higher. Removal fees are $0.52 per standard-size unit and $0.99 per oversize unit (indicative, check Amazon's fee schedule). Allocate at least 5-10% of your inventory value for these costs.

• Step 1: Check your IPI score and review the breakdown
• Step 2: Create a plan to reduce excess inventory by 20% within 30 days
• Step 3: Fix any stranded inventory within a week
• Step 4: Set a monthly review calendar and track progress
• Step 5: Adjust your budget for storage fees based on your IPI trend

Key Takeaways

In summary, Amazon FBA IPI is a critical metric for sellers, impacting storage costs and capacity. By understanding its components and avoiding common mistakes, you can maintain a score above 400 and even reach 500+. Start by auditing your current score, then implement a weekly review process and budget for storage fees. For further guidance, consult Amazon's official IPI help pages and consider using inventory management tools to automate tracking.

This article is compiled by kuajing168.cn for reference only. Please refer to the official announcements of each platform for the latest policies and rates.