Inventory is cash in disguise — every dollar sitting on a shelf is a dollar not funding growth. The inventory turnover ratio tells you how many times a business sells through its stock each period: high turnover means lean, fast-moving operations; low turnover means capital trapped in slow-moving goods.
This free inventory turnover calculator takes COGS plus beginning and ending inventory, computes average inventory, the turnover ratio and days sales of inventory (DSI) — with a plain-English reading of the result. Instant, private, in your browser.
Turnover ratio · days sales of inventory
What is a "good" turnover ratio? ⓘ
Please enter a COGS above zero and inventory values of zero or above.
Uses COGS (not revenue) in the numerator per standard accounting practice — revenue would inflate the ratio with profit margin. Estimates only.
How to Use This Calculator
- Enter COGS — the cost of goods sold for the period, from the income statement.
- Enter beginning and ending inventory — stock values from the balance sheet at period start and end.
- Set the period length (365 days = one year; use 90 for a quarter).
- Click Calculate Turnover for average inventory, the turnover ratio, DSI and an interpretive reading.
Inventory turnover formulas
Inventory Turnover = COGS ÷ Average Inventory
Days Sales of Inventory (DSI) = Period Days ÷ Turnover
Worked example
COGS = $900,000; beginning inventory $120,000; ending inventory $80,000; 365-day year.
Average inventory = ($120,000 + $80,000) ÷ 2 = $100,000
Turnover = $900,000 ÷ $100,000 = 9.00×
DSI = 365 ÷ 9 = 40.6 days — stock sells through roughly every six weeks. Very efficient.
Benchmarks and what moves the ratio
- Typical ranges: grocery/FMCG 10–15×, electronics 6–8×, apparel 4–6×, automotive 2–4×, luxury 1–2×. Compare within your industry, not across them.
- Raising turnover: tighter demand forecasting, smaller batch orders, clearing slow-movers with promotions, just-in-time purchasing.
- Too high can hurt: extreme turnover risks stockouts and lost sales — the optimum balances carrying cost against availability.
- Trend matters most: turnover drifting down quarter after quarter is an early warning of overbuying or softening demand.
Where DSI Fits: The Cash Conversion Cycle
Days sales of inventory is one leg of a bigger measure your accountant cares about: the cash conversion cycle, CCC = DSI + DSO − DPO, where DSO is how fast customers pay you (days sales outstanding) and DPO is how slowly you pay suppliers (days payables outstanding). The cycle counts the days your cash is locked up between paying for stock and collecting from sales.
Extend the worked example above: DSI is 40.6 days. If customers pay in 30 days on average (DSO) and you pay suppliers at 45 days (DPO), the cycle is 40.6 + 30 − 45 = 25.6 days of cash tied up in operations. Every day you shave off DSI shortens that cycle by a full day — which is why turnover work shows up directly in cash flow, not just on warehouse shelves. Our cash cycle calculator runs the full three-part calculation.
Frequently Asked Questions
What is a good inventory turnover ratio?
It is industry-relative: grocers run 10–15×, apparel 4–6×, car makers 2–4×. A “good” ratio beats your direct competitors and is stable or rising — the calculator’s reading gives a rough cross-industry sense.
Should I use COGS or revenue in the formula?
COGS — the accounting standard. Revenue includes profit margin, which inflates the ratio and makes comparisons meaningless. This calculator uses COGS throughout.
What is days sales of inventory (DSI)?
DSI = 365 ÷ turnover: the average days each dollar of inventory sits before selling. A 9× turnover means ~41 days of stock on hand — intuitive for cash-planning.
How can a business improve inventory turnover?
Forecast demand more tightly, order smaller batches more often, discount or bundle slow-moving SKUs, negotiate supplier lead times down, and track turnover by product line — aggregate ratios hide dead stock.
Can turnover be too high?
Yes. Ultra-high turnover can mean chronic stockouts, rushed reorders at premium freight cost, and lost sales. The goal is the turnover that maximizes profit, not the maximum turnover itself.
Why average beginning and ending inventory?
Inventory swings with seasons and purchase cycles; averaging smooths the spikes so one unusual month-end doesn’t distort the ratio. Firms with strong seasonality sometimes average quarterly balances instead.
What is the difference between DSI and DIO?
There is none — they are two names for the same number. Days sales of inventory (DSI) and days inventory outstanding (DIO) both equal period days ÷ turnover (or average inventory ÷ COGS × days). Accountants and textbooks use the terms interchangeably.
Should I calculate turnover for each product or for the whole business?
Both, in that order. The whole-business ratio is a quick health check, but an average can hide a warehouse where half the SKUs fly and half never move. Drilling into turnover by product line or category exposes the dead stock — and the surprise bestsellers — that the aggregate conceals.
How do I calculate inventory turnover for a quarter?
Use the quarter’s COGS and inventory values, and set the period to about 91 days so the DSI comes out in days. The ratio itself is then “times per quarter” — multiply by roughly 4 to compare it with annual benchmarks, keeping in mind that seasonal quarters are not typical quarters.
Final Thoughts
Every figure on this page was computed live by the tool above — try your own numbers and see how the math responds.
Find out how fast your stock really moves — calculate turnover above, then explore our other free business finance tools.