Inventory Turnover Ratio: How to Calculate and Improve It

The formula and what it measures

Inventory turnover equals cost of goods sold divided by average inventory for the same period. It tells you how often stock is sold and replaced.

The formula is simple:

Inventory turnover = Cost of goods sold / Average inventory

Use cost of goods sold, not sales, so both sides of the fraction are measured at cost. Average inventory is usually the beginning balance plus the ending balance, divided by two. For seasonal businesses, averaging twelve month-end balances gives a truer picture. If you need help with the numerator, see calculating cost of goods sold.

The ratio belongs to a family of efficiency measures. The overview of the activity ratio shows how it fits alongside receivables and payables turnover.

A worked example with round numbers

If cost of goods sold is $600,000 and average inventory is $100,000, turnover is 6. You sell through your stock six times a year.

Consider an illustrative home goods retailer. Over the year, cost of goods sold was $600,000. Inventory was $90,000 at the start and $110,000 at the end, so average inventory was $100,000.

Turnover = $600,000 / $100,000 = 6 times a year.

To convert this to days, divide 365 by the ratio: 365 / 6 is about 61 days. That is the average time a unit sits before it sells, often called days sales of inventory.

Same sales, three different amounts of cash tied up in stock.

What counts as a good ratio

There is no universal target. A grocer turns stock many times a year; a furniture or jewelry seller turns it far fewer. Compare against your own history and similar businesses.

Perishable goods demand high turnover or they spoil. High-ticket, slow-moving goods are expected to turn slowly. A ratio that is excellent for a furniture store would signal trouble in a restaurant.

Judge your number three ways:

• Against your past. Is it rising, falling or stable?
• Against your industry. Trade associations and your accountant can share typical ranges.
• Against your margin. A low-turn business needs a higher margin to earn the same return on the cash tied up.

Very high turnover is not always good. It can mean you are under-stocked, losing sales to stockouts, or ordering in small quantities at higher unit prices. Look at fill rates and lost-sale signals alongside the ratio.

Why slow turnover quietly drains cash

Every dollar in unsold stock is a dollar you cannot use for payroll, rent or growth. Slow turnover also adds storage, insurance, shrinkage and markdown costs.

Inventory feels like an asset, but until it sells it is cash locked up. Say you hold $100,000 of stock that turns twice a year, while a competitor holds $50,000 that turns four times for the same sales. You have an extra $50,000 sitting idle.

Carrying costs add up too: storage space, insurance, handling, theft and damage, and the risk that products go out of style or expire. Many owners put these at a meaningful share of inventory value each year, though the number depends heavily on the product.

This is the connection between turnover and your cash position. A profitable business can still run out of cash because the profit is stuck in stock. Our guide on cash flow versus profit explains the gap, and negative cash flow shows how to respond.

Practical ways to raise your turnover

Cut slow movers, order smaller quantities more often, negotiate supplier terms, and price or promote aging stock before it becomes dead stock.

Work through these steps in order:

1. Rank every product by sales and margin. Identify the bottom tier that has not sold in 90 days or more.
2. Clear aging stock. Bundle, discount or return what you can. A small loss now frees cash for items that sell.
3. Reorder by data, not habit. Set reorder points from actual weekly sales and supplier lead time.
4. Order smaller batches more often if the supplier allows, even if the unit price is slightly higher. Compare the extra unit cost with the carrying cost saved.
5. Negotiate terms. Longer payment terms mean you may sell the goods before the supplier bill is due.
6. Forecast seasonal demand so you do not over-buy for a peak that does not come.

For the bookkeeping side, see inventory accounting.

When funding inventory makes sense

Funding stock is sensible when the goods will sell quickly and the margin covers the cost. It is risky for slow movers.

Sometimes the right move is to buy more, not less: a bulk discount, a busy season, or a new product line with proven demand. The test is how fast the stock turns into cash compared with how fast the funding must be repaid.

Here is an illustrative case. You borrow to buy $40,000 of fast-selling product that turns every 45 days at a 45 percent gross margin. The goods sell for about $72,700, a gross profit near $32,700. If funding costs $4,500 in total, the math works. If the same $40,000 were slow stock taking 8 months to sell, the repayment would arrive long before the sales do.

Walk through our inventory funding payback math before you borrow. A business line of credit suits repeat purchases, while working capital can cover a one-time buy. ROI Funder considers 500+ FICO, 6+ months in business and $20,000+ monthly revenue.