Inventory Turnover Ratio and the Cash It Traps
Inventory turnover ratio: cost of goods divided by average inventory. How slow stock traps cash, what to cut first, and how it shows up in a 13-week forecast.
Jonathan Napitupulu
Inventory turnover is cost of goods sold divided by average inventory. A low number means stock sits. Sitting stock is cash you already spent. Service firms can skip this page. Everyone who buys goods before they sell them cannot.
Why turnover is a cash metric
You pay suppliers, often before customers pay you. The warehouse is a loan to the future. Hackett’s working-capital survey, reported by CFO.com in September 2026, put the total working-capital opportunity at $1.94 trillion for large U.S. nonfinancial companies, with days inventory outstanding up 0.6 days in 2025. Even giants trap more cash in stock. A small firm feels it as an overdraft.
Clockwork.ai’s July 2026 analysis found profitable firms still heading for a 90-day cash crunch. Inventory is a classic reason: the P&L booked a healthy margin on goods that have not sold.
How to compute it without a textbook
Take delivery cost of goods sold for a year or a quarter, annualised if needed. Divide by average inventory (beginning plus ending, halved). Then invert: days in inventory is about 365 divided by turnover. If days in inventory exceed your cash buffer, you are overstocked relative to survival, not relative to a merchandising dream.
SoFi’s 2026 survey found 55 percent of owners had three months of cash or less. Three months is roughly 90 days. Stock that turns twice a year does not fit that buffer.
What to cut first
Dead SKUs. Safety stock on items that never stock out. “Good deal” purchases that ignore the 13-week forecast. Xero’s Q2 2026 figures showed businesses waiting 29.3 days to get paid. If you also hold 90 days of stock, cash conversion is brutal even if margin looks fine.
Bluevine’s October 2025 survey found 38.7 percent of owners could not cover a month of expenses. Do not buy a container because the unit cost is pretty. Buy against dated demand.
Protiviti’s 2026 survey put cash management in the CFO top three. Inventory policy is cash policy. Put weeks of stock next to weeks of cash on one screen.
Service firms that still have “inventory”
Unbilled work in process is cousin to stock. If you build for weeks before invoicing, you have trapped cash without a warehouse. Invoice milestones.
Frequently asked questions
What is inventory turnover ratio?
Cost of goods sold divided by average inventory. Higher usually means cash is less trapped, if you are not starving the shelf.
What is a good number?
It depends on the category. Compare to your own cash buffer and stockout history, not to a generic benchmark.
How does it relate to days inventory outstanding?
Days in inventory is roughly 365 divided by turnover. That is the number to sit next to runway.
Should I discount dead stock?
Usually yes. Cash today beats a perfect margin on goods that will not move.
What if I am a service business?
Skip SKU turnover. Watch unbilled work in process instead.
How often should I review it?
Monthly for the ratio, weekly for SKUs that have not moved.