The Numbers That Matter
Tracking the right KPIs transforms inventory management from a guessing game into a data-driven discipline. Here are the metrics every retailer should monitor.
1. Shrinkage Rate
Formula: (Recorded Inventory - Physical Count) / Recorded Inventory x 100
Benchmark: Below 1.5% is healthy; below 1% is excellent
Why it matters: This is your single most important inventory health metric. Track it after every audit and chart the trend over time. If it is rising, something is wrong. If it is falling, your controls are working.
2. Inventory Turnover Rate
Formula: Cost of Goods Sold / Average Inventory Value
Benchmark: Varies by retail type (4-6 for general retail, 8-12 for fast fashion, 2-4 for furniture)
Why it matters: How many times per year you sell and replace your entire inventory. Higher is generally better -- it means your money is not sitting on shelves. Low turnover means dead stock.
3. Sell-Through Rate
Formula: Units Sold / (Units Sold + Units On Hand) x 100
Benchmark: 80%+ within the planned selling period
Why it matters: Shows how effectively you are converting inventory to sales. Low sell-through means you are over-buying or pricing too high.
4. Days of Inventory (DOI)
Formula: Average Inventory / Average Daily Sales
Benchmark: 30-60 days for most retailers
Why it matters: How many days of sales your current inventory would cover if you stopped restocking. Too high means excess capital tied up. Too low means stockout risk.
5. Stockout Rate
Formula: Number of Stockout Events / Total SKUs x 100
Benchmark: Below 5%
Why it matters: Every stockout is a lost sale. Track which products run out and how often to improve your reorder points.
6. Gross Margin Return on Inventory (GMROI)
Formula: Gross Profit / Average Inventory Cost
Benchmark: Above 2.0 (for every $1 in inventory, you earn $2 in gross profit)
Why it matters: The ultimate measure of inventory investment efficiency. It tells you whether your inventory is earning its keep.
7. Audit Accuracy Rate
Formula: Items Counted Correctly / Total Items Counted x 100
Benchmark: Above 95%
Why it matters: Measures how well your counting process is working. If accuracy is low, you need better training or tools.
Putting It All Together
You do not need to track all seven KPIs from day one. Start with shrinkage rate and inventory turnover -- these two numbers give you the clearest picture of inventory health. Add the others as your data collection matures.
The key is consistency: measure the same way every time so you can track trends. A shrinkage rate of 1.2% is meaningless in isolation -- but a trend from 2.1% to 1.5% to 1.2% over three quarters tells you your audit program is working.