Finance

Inventory Turnover Calculator

Calculate your inventory turnover ratio, days inventory outstanding, or implied average inventory from your cost of goods sold and stock data.

Enter values above to see the result.

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Inventory Turnover Formula

Inventory turnover measures how efficiently a business converts stock into sales. Both the ratio and days metric are derived from COGS and average inventory.

Turnover Ratio = COGS ÷ Average Inventory

Days Inventory Outstanding = 365 ÷ Turnover Ratio

Example: $500,000 COGS ÷ $100,000 avg inventory = 5× turns = 73 days

Why Inventory Turnover Matters

Inventory represents tied-up capital. Every day stock sits in a warehouse, it incurs storage costs, insurance, and the risk of obsolescence. A high turnover ratio means capital is being recycled quickly into revenue, which improves cash flow and reduces the working capital a business needs to operate.

The days inventory outstanding metric directly feeds into the cash conversion cycle. Lower DIO shortens the time between paying for inventory and collecting payment from customers, which is one of the most important levers for improving a business's liquidity.

Track inventory turnover quarterly and compare it against industry benchmarks and your own historical trend. A declining trend may signal that products are becoming stale or that purchasing decisions are outpacing demand.

Frequently asked questions

What is the inventory turnover ratio?
The inventory turnover ratio measures how many times a company sells and replaces its inventory over a given period, typically one year. A higher ratio indicates that products are selling quickly and that inventory is being managed efficiently. A lower ratio may suggest overstocking, slow sales, or obsolete inventory sitting on shelves.
How is inventory turnover calculated?
Inventory turnover is calculated by dividing the cost of goods sold (COGS) by the average inventory for the period. Average inventory is typically the opening inventory plus closing inventory divided by two. For example, if COGS is $500,000 and average inventory is $100,000, the turnover ratio is 5, meaning stock was turned over five times during the year.
What is a good inventory turnover ratio?
A good inventory turnover ratio varies by industry. Grocery and fast-moving consumer goods businesses typically turn inventory 15 to 30 times per year. Furniture or jewellery retailers may turn inventory only 2 to 4 times per year. In general, a higher ratio is better as long as you are not running out of stock and missing sales opportunities.
What is days inventory outstanding (DIO)?
Days inventory outstanding is the average number of days a business holds inventory before selling it. It is calculated as 365 divided by the inventory turnover ratio. A DIO of 73 days means inventory sits for about 10 weeks on average. Lower DIO generally means faster cash conversion and lower storage costs.
Should I use COGS or revenue to calculate inventory turnover?
The standard and more accurate method uses cost of goods sold (COGS) rather than revenue, because both COGS and inventory are measured at cost. Using revenue would overstate the ratio because revenue includes the profit markup. Some analysts use revenue for simplicity when COGS is not available, but COGS is the preferred approach for comparability.
How can I improve my inventory turnover ratio?
To improve inventory turnover, you can reduce reorder quantities and order more frequently, discontinue or discount slow-moving products, improve demand forecasting to avoid overstocking, negotiate just-in-time delivery with suppliers, and use inventory management software to track stock levels in real time. Each of these reduces the average inventory balance without necessarily cutting into sales.

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