Understanding Stock Turnover Ratio: Key Insights & Why It Matters

Maybe you’ve run out of space in your warehouse. Or perhaps you don’t have enough sales inventory to meet demand. For many inventory problems, calculating your stock turnover ratio could be the first step toward a solution.

In this article, we’ll define stock turnover ratios, provide inventory turnover formulas, and reveal good inventory management practices for optimized inventory levels.

What Is Stock Turnover Ratio (STR)?

Stock turnover ratio (STR) is an inventory management metric measuring the rate at which a company runs through its full inventory within a given period (e.g., a quarter or fiscal year). STR helps companies determine the financial efficiency of their inventory strategy.

There are two ways to measure STR: costs compared to average inventory and value compared to current inventory.

Option 1: Cost of Goods Sold (COGS)

The first method measures cost of goods sold (COGS) relative to your average inventory levels in a given period. This is also known as inventory turnover ratio (ITR). A high inventory turnover ratio typically indicates efficient sales.

Option 2: Value of Goods

The second method measures the value of inventory sold in a specific time period relative to your current amount of inventory. This indicates whether you’ve purchased appropriately for actual demand.

Later, we’ll share the formulas used to calculate these ratios. But first, let’s explore why stock turnover ratio matters.

Understanding Stock Turnover Ratios for Inventory Management

Stock turnover matters because it helps businesses understand how efficiently they’re buying, selling, and replacing their inventory.

A high inventory turnover rate can indicate strong sales and high operational efficiency — although an extremely high STR suggests you may not carry enough inventory. A low inventory turnover rate may indicate weak sales or inefficient management of inventory. Companies with a low turnover ratio may carry obsolete inventory or dead stock — items you can’t sell and must discard.

Calculating inventory turnover can be the first step toward identifying and resolving poor inventory management practices. It also carries significant implications for other financial metrics, including profitability. To make informed decisions about purchases and stock levels, it’s essential to monitor and adjust STR.

Calculating metrics like this can be time-consuming, complex, and prone to manual errors. But advanced software, such as a computerized maintenance management system (CMMS), removes the guesswork through automation and advanced reporting.

How To Calculate Stock Turnover Ratio, With Examples

Use these formulas to calculate your stock turnover ratio.

Option 1: Calculate Inventory Turnover Ratio With Cost of Goods Sold (COGS) Relative to Average Inventory

Start by calculating your cost of goods sold (COGS) for a given time period:

COGS = Beginning Inventory + Inventory Purchases in a Given Period – Ending Inventory Balance

For example, if you started a year with $1,000,000 in inventory, bought $250,000 in additional inventory, and ended the year with $300,000 in inventory, your COGS is $950,000.

Next, calculate your inventory turnover ratio:

ITR = COGS / Average Value of Total Inventory

If your average inventory value is $150,000 and your COGS is $950,000, then your ITR is 6.33, meaning you replace your inventory about 6.3x per year (nearly every 8 weeks). This indicates fairly high inventory turnover and efficient management.

Option 2: Calculate Stock Turnover Ratio With Value of Goods Used Relative to Current Inventory Value

This calculation is simple:

STR = Value of Goods Sold and/or Used in a Given Period / Value Currently Held

For example, if you sold $250,000 worth of goods and used another $50,000 on maintenance in the past year, that’s $300,000 sold and used this year.

Now, let’s say you currently hold $250,000 in inventory. Divide $300,000 by $250,000 to get your STR of 1.2, meaning you replace your company’s inventory about 1.2x per year. This low number may indicate inefficient management.

What Is a Good Stock Turnover Ratio?

Ideal inventory turnover ratio varies considerably due to different industry averages and market fluctuations. But in general, a high turnover ratio is preferable.

CSIMarket tracks companies across sectors to calculate average inventory turnover ratios. Here’s how each sector performs, from best to worst:

1. Financial: 64.30
2. Utilities: 63.03
3. Services: 11.29
4. Energy: 11.29
5. Retail: 10.11
6. Transportation: 6.55
7. Consumer Discretionary: 5.29
8. Basic Materials: 5.05
9. Consumer Non-Cyclical: 4.95
10. Technology: 4.75
11. Conglomerates: 3.80
12. Capital Goods: 3.07
13. Healthcare: 2.84

Benefits of Tracking STR

Tracking your company’s inventory turnover ratio has widespread benefits.

• Improve operational efficiency: Understanding inventory turnover helps you manage inefficiencies, whether from excess inventory or insufficient inventory.
• Monitor business performance: Stock turnover ratio helps you compare current and past performance to make more informed decisions.
• Streamline maintenance operations: STR includes internal inventory such as spare parts and equipment. Tracking STR helps you achieve the right inventory mix and schedule maintenance based on your inventory purchase schedule.
• Reduce storage costs: Retaining too much inventory increases your carrying costs. Monitoring STR helps you meet customer demand and purchase only the amount of items your company sells.
• Optimize working capital: Efficient inventory practices leave you with less unsold inventory, freeing up capital for other important expenses.

With a good inventory turnover ratio, you can improve on each of these areas.

Limitations of Inventory Turnover Metrics

Your stock turnover ratio won’t tell you everything about the health of your company. The ratio doesn’t take the following into account:

• Inaccurate data or valuations: Stock turnover ratio depends on accurate data. Improper valuation or miscalculation invalidates the ratio.
• Balance of all inventory items: Cost of goods sold includes both items your business sells and inventory used in normal business operations. It doesn’t distinguish between the two, which can distort your efficiency ratio.
• Seasonality: Regardless of industry, inventory turnover rate typically changes through the seasons. Stock turnover ratio doesn’t reveal variable holding periods or help you forecast inventory needs by season.
• Supply chain disruptions: Shipment delays can temporarily lower your inventory levels and require the use of safety stock. It may result in lost sales opportunities. Your stock turnover ratio can’t account for these disruptions.
• Shifts in market demand: Since the inventory turnover ratio measures averages (average value, average inventory levels), it won’t reflect customer demand fluctuations.
• Overall financial health: Tracking inventory turnover is useful for many reasons, but it’s just one metric. It can’t reflect or predict complete financial performance.

While stock turnover ratio may reveal inefficient inventory management, it’s not a comprehensive measure of success.

How Can You Improve Inventory Turnover?

Managing inventory differently can fix a low inventory turnover ratio — and the right software can simplify everything. A CMMS can detail inventory levels and holding costs, highlight trends, and enable data-driven demand forecasting and purchasing decisions.

Could a CMMS be the key to efficient inventory management for your company? Try a free demo of eMaint CMMS today.