Inventory Performance Index Calculator

Calculate your Amazon IPI score and understand how to improve your inventory performance. Maintain a healthy IPI to avoid storage restrictions.

IPI Calculator

IPI Score
IPI Score: -
Performance Level: -
Status: -
Score Breakdown
Sell-Through: -
Excess Inventory: -
Stranded Inventory: -
Availability: -

How IPI is Calculated

Amazon's Inventory Performance Index (IPI) is calculated based on four key metrics: Sell-Through Rate (25%), Excess Inventory (25%), Stranded Inventory (25%), and Availability (25%). The formula is: IPI = (ST Γ— 0.25 + EI Γ— 0.25 + SI Γ— 0.25 + AV Γ— 0.25) Γ— 10. Where ST = Sell-Through Score (0-100), EI = Excess Inventory Score (0-100), SI = Stranded Inventory Score (0-100), AV = Availability Score (0-100).

Real Example: Calculating IPI Score

Let's calculate IPI for a seller with these metrics: Sell-Through Rate = 8%, Excess Inventory = 15%, Stranded Inventory = 5%, In-Stock Rate = 95%.

Step 1: Sell-Through Score
Sell-Through Score = min(100, ST Γ— 12.5) = 8 Γ— 12.5 = 100 (maxed out)

Step 2: Excess Inventory Score
Excess Inventory Score = max(0, 100 - EI Γ— 4) = 100 - 15 Γ— 4 = 100 - 60 = 40

Step 3: Stranded Inventory Score
Stranded Inventory Score = max(0, 100 - SI Γ— 10) = 100 - 5 Γ— 10 = 100 - 50 = 50

Step 4: Availability Score
Availability Score = In-Stock Rate = 95

Step 5: Calculate IPI
IPI = ((100 Γ— 0.25) + (40 Γ— 0.25) + (50 Γ— 0.25) + (95 Γ— 0.25)) Γ— 10
= (25 + 10 + 12.5 + 23.75) Γ— 10 = 71.25 Γ— 10 = 712.5

An IPI score of 712 is considered excellent. Sellers with IPI β‰₯ 500 enjoy full storage capacity, while those below 500 face restrictions.

Key Factors That Impact Your IPI

  • Sell-Through Rate: Higher rates improve IPI; aim for 7-10% monthly
  • Excess Inventory: Keep under 10% to avoid penalties
  • Stranded Inventory: Zero is ideal; fix listing issues immediately
  • In-Stock Rate: Maintain 95%+ for best scores

What This Calculator Includes (and What It Doesn't)

This calculator estimates your IPI based on Amazon's public formula. Not included: Amazon's proprietary weighting adjustments, seasonality factors, and category-specific benchmarks. Your actual IPI may differ from this estimate. Check Seller Central for your official score.

Frequently Asked Questions About IPI

What's a good IPI score?
A good IPI score is 500 or above. Scores between 500-700 are considered healthy, while scores above 700 are excellent. Sellers with IPI below 500 may face storage limits and increased fees.
How often is IPI updated?
Amazon updates IPI scores weekly, typically on Monday mornings. However, the score is based on a rolling 90-day window, so changes take time to reflect. Focus on consistent improvement over time.
How can I improve my IPI score?
To improve IPI: (1) Increase sell-through by running promotions or adjusting pricing, (2) Reduce excess inventory by creating removal orders or bundling slow items, (3) Fix stranded inventory by updating listings or creating removal orders, (4) Maintain high in-stock rates by optimizing reorder timing.
What happens if my IPI is below 500?
If your IPI falls below 500, Amazon may restrict your storage capacity and increase storage fees. During Q4, the threshold increases to 550 for expanded holiday storage. It's crucial to maintain a healthy IPI to avoid these penalties.

Understanding Amazon IPI

The Inventory Performance Index (IPI) is Amazon's way of measuring how efficiently you manage your inventory. A higher IPI score means you're turning over inventory quickly, minimizing excess stock, and keeping popular items in stock. Track your IPI regularly and take action when it falls below 500.

Disclaimer: This calculator provides estimates based on publicly available data. Amazon's actual IPI calculation includes proprietary factors not disclosed publicly. Your official IPI score is available in Seller Central. This tool is for educational purposes only.