Inventory Turnover Ratio: Formula, Benchmarks and How to Improve It

If you sell physical products, cash sitting on a shelf is cash you cannot spend on ads, payroll or the next launch. The inventory turnover ratio is the simplest way to see how hard your inventory is working. It is also one of the numbers buyers and lenders look at first.

Here is how to calculate it properly, what the number is telling you, and the practical moves that improve it without starving your best sellers.

The formula

Inventory turnover measures how many times you sell through your average inventory in a period.

Inventory turnover = Cost of goods sold ÷ Average inventory

Average inventory is usually the beginning balance plus the ending balance, divided by two. For a more accurate picture, especially in seasonal businesses, average the month end balances across the year.

The companion number is days inventory outstanding, sometimes called days on hand:

Days inventory outstanding = 365 ÷ Inventory turnover

Owners tend to find days easier to feel. “We hold about 90 days of stock” means more in a planning meeting than “we turn four times a year.”

A worked example

Illustrative example, not a specific client. Say an online home goods brand had $1.8 million in cost of goods sold last year. Inventory was $500,000 at the start of the year and $700,000 at the end.

So the brand holds roughly four months of stock. Whether that is good depends on lead times, seasonality and margin. But if its supplier ships in 45 days, four months on hand probably means cash is trapped in slow SKUs.

What is a good inventory turnover ratio?

There is no universal target. A grocery store turns stock far faster than a furniture retailer. The best benchmark is your own history and close competitors.

For a broad reference point, the U.S. Census Bureau publishes a monthly inventories to sales ratio for retailers. As of August 2026, U.S. retailers held inventory equal to about 1.36 months of sales, according to Census data published through the St. Louis Fed’s FRED database. That roughly equals 40 days of sales at retail value. Your number will differ by category, but if you are holding several times that, it is worth asking why.

Why the number can lie

Turnover is only as good as the inputs. These are the problems we find most often:

• COGS is not real. If inventory purchases are expensed when paid, cost of goods sold just tracks your purchasing, not your sales.
• Landed costs are missing. Freight, duties and inbound fees belong in inventory cost. Leaving them out understates inventory and distorts margins.
• Counts are stale. If the books say $700,000 but the warehouse holds $550,000 of sellable goods, the ratio is meaningless.
• Dead stock is hiding the winners. A healthy overall ratio can mask a few SKUs that have not moved in a year.

Fixing these starts with accurate bookkeeping that records inventory on the balance sheet and books cost of goods sold from what actually shipped.

Practical ways to improve turnover

Look at it by SKU, not just in total

Rank products by turnover and gross margin together. Fast sellers with good margin deserve priority on cash. Slow sellers with weak margin are candidates for bundles, markdowns or discontinuing.

Set reorder points from real lead times

Reorder points should reflect supplier lead time, sales velocity and a sensible safety stock. Many brands order by habit or by supplier minimums, which bloats stock.

Negotiate smaller, more frequent orders

Even a slightly higher unit cost can be worth it if it cuts the cash tied up in stock by a meaningful amount. Run the math both ways.

Clear dead stock deliberately

Set a rule, for example anything without a sale in 180 days gets reviewed. Liquidating slowly almost always costs more than acting early.

Forecast with cash in mind

Inventory buys are often the largest cash outflow for product companies. Linking purchase plans to a weekly cash forecast, the kind a fractional CFO maintains, keeps a big order from colliding with payroll.

Why buyers care

If you ever sell the business, buyers will test inventory hard. Slow moving or obsolete stock often gets written down in a quality of earnings review, and inventory levels feed straight into the working capital target. Clean inventory records make that conversation shorter and protect your price. That is a big part of how we prepare owners for a sell side QoE and valuation.

Our inventory management services focus on exactly these pieces: accurate counts, real landed costs, SKU level reporting and purchase planning.

Frequently asked questions

How do you calculate inventory turnover ratio?

Divide cost of goods sold for the period by average inventory for the same period. Average inventory is usually beginning plus ending inventory divided by two, or an average of month end balances.

What is a good inventory turnover ratio for ecommerce?

It depends on the category, lead times and seasonality. Compare against your own history and close competitors, and look at days of inventory relative to supplier lead time.

Is a high inventory turnover always good?

Not always. Very high turnover can mean you are running out of stock and losing sales. The goal is enough stock to meet demand without tying up excess cash.

What is days inventory outstanding?

It is the average number of days inventory sits before it is sold. It equals 365 divided by the inventory turnover ratio.

Let’s talk about your numbers

If you are not sure what your real turnover is, or you suspect cash is stuck in the warehouse, we would be glad to look at it with you in a free meeting. No pressure, just a clear read on your numbers. See our inventory management page or contact our Miami team.