Inventory Turnover Calculator

Measure how many times stock sells and how long it sits.

Cost of goods sold

Annual cost of goods sold.

Average inventory

Typically (opening + closing) ÷ 2.

Results update as you type.

Turnover ratio

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Days to sell—

How it works

An inventory turnover calculator shows how efficiently a business converts its stock into sales, reporting both the turnover ratio — how many times the average inventory was sold and replaced over the year — and the average number of days a unit sits on the shelf before selling. You enter the annual cost of goods sold and the average inventory held during the period, and the tool returns both figures instantly. Turnover matters because inventory is cash frozen in physical form: every dollar tied up in unsold stock is a dollar not available for wages, marketing or growth, and slow-moving goods risk obsolescence, spoilage and storage cost. A high turnover ratio signals brisk sales and lean, well-managed stock, while a low ratio warns of overbuying, weak demand or a catalogue clogged with items that will not shift. The divide method used here compares the cost of what actually sold against the cost of what was typically held, which is why cost of goods sold rather than revenue sits on top — it keeps both numbers on the same cost basis and avoids inflating the ratio with the profit margin. Retailers, wholesalers and manufacturers track inventory turnover to fine-tune ordering, spot dead stock, negotiate supplier terms and free up trapped cash. Read alongside days-to-sell, it turns an abstract ratio into a concrete sense of how quickly the shelves clear.

Formula

Turnover = COGS ÷ average inventory · Days to sell = 365 ÷ turnover

Cost of goods sold measures the cost of everything sold during the year, and average inventory is the typical cost value of stock held, usually opening plus closing inventory divided by two. Dividing COGS by average inventory gives the turnover ratio — the number of times stock was cleared and replenished. Dividing 365 by that ratio converts it into the average days a unit remains in inventory before it sells, translating the ratio into an intuitive timeframe.

Source:Standard financial (inventory) accounting

We review all our tools from time to time to ensure accuracy.

Worked example

Cost of goods sold:500000Average inventory:100000

Turnover = 500,000 ÷ 100,000 = 5×. Days to sell = 365 ÷ 5 = 73 days per cycle.

How to use this calculator

1
Enter your values
Enter cost of goods sold and average inventory.
2
Adjust the options
Fine-tune any options to match your situation.
3
Read your result
Turnover ratio updates instantly as you type — no button to press.

Frequently asked questions

What is a good inventory turnover ratio?

It varies sharply by industry. Grocers and fast-fashion retailers may turn stock a dozen or more times a year because products are perishable or trend-driven, while furniture, jewellery and industrial equipment turn far more slowly and still operate healthily. The best benchmark is your own sector and your own history. A ratio that is rising usually means leaner, better-matched stock, while a falling ratio hints at overbuying or softening demand that ties up cash.

Why use COGS instead of revenue?

Inventory is recorded at cost, not at its selling price, so dividing cost of goods sold by average inventory keeps both figures on the same cost basis. Using revenue instead would include your profit margin in the numerator but not the denominator, artificially inflating the ratio and making turnover look faster than it really is. Sticking to COGS produces a true measure of how many times the physical stock cycled through the business during the period.

What does days to sell tell me?

Days to sell, also called days sales of inventory, converts the turnover ratio into the average number of days a unit sits in stock before it is sold. It is often more intuitive than the ratio itself: knowing that stock takes 73 days to clear is easier to act on than knowing turnover is five times a year. Shorter days-to-sell frees cash faster and reduces the risk of obsolescence, spoilage and markdowns on aging inventory.

How do I calculate average inventory?

The simplest method adds the inventory value at the start of the period to the value at the end and divides by two, smoothing out a single opening or closing snapshot that might be unusually high or low. For businesses with strong seasonal swings, averaging monthly or quarterly balances gives a more representative figure. The goal is a value that reflects the typical amount of stock carried across the whole period rather than one arbitrary date.

How can I improve inventory turnover?

Match purchasing more closely to real demand using sales data, and avoid overordering slow lines just to hit supplier discounts. Clear dead and aging stock through promotions to release trapped cash, tighten reorder points, and shorten lead times so you can hold less safety stock. Improving turnover is a balance, though — pushing it too high risks stockouts and lost sales, so the aim is fast, reliable flow rather than the highest possible ratio.