庫存週轉率計算器：週轉率與DSI
Measure how often inventory turns and how many days stock remains on hand.
Enter cost of goods sold and either average inventory or beginning and ending inventory values.
庫存週轉率計算器：週轉率與DSI
Measure how often inventory turns and how many days stock remains on hand.
About Inventory Turnover and Days Sales in Inventory
Inventory turnover measures how many times a company sells and replaces its stock during a period. A high turnover can mean strong demand and tight working capital; a low turnover can mean overstocking, obsolescence, or a deliberately deep assortment. Days sales in inventory (DSI) restates the same relationship as the number of days inventory would last at the current cost of goods sold.
The inventory turnover calculator uses inventory turnover = COGS ÷ average inventory and DSI = 365 ÷ inventory turnover. If you enter average inventory directly, that figure is used. If you leave average inventory blank and supply beginning and ending balances, average inventory is (beginning + ending) ÷ 2. Daily COGS is annual COGS ÷ 365. With $50,000 of COGS and $10,000 average inventory, turnover is 5.00 and DSI is 73.00 days. With $120,000 COGS, $20,000 beginning inventory, and $30,000 ending inventory, average inventory is $25,000, turnover is 4.80, and DSI is 76.04 days.
Retailers, manufacturers, and wholesalers use these ratios in working-capital reviews, lender covenants, and merchandising decisions. Compare a grocer with a furniture dealer only after you accept that industry velocity differs. Seasonal businesses should use a 12-month COGS and an average of several inventory snapshots, not a single year-end balance that may be window-dressed.
COGS and inventory must use the same costing method and currency. Mixing retail selling prices with cost-based inventory inflates turnover. The 365-day convention is a standard annualization, not a claim that the firm operates every calendar day. LIFO versus FIFO, write-downs, and consignment stock all change the ratio without a change in physical units. The calculator does not benchmark a “good” turnover; it only reports the arithmetic so you can compare periods or peers on a consistent basis. When a ratio jumps after a write-down, check whether physical units actually moved or whether the denominator simply shrank. Document the costing method and the date of each inventory snapshot whenever turnover supports a lending covenant or a merchandising reset.
Inventory Turnover Calculator Worked Examples
Use these worked scenarios to check inputs and understand how the estimate responds.
| Inputs | Result | Interpretation |
|---|---|---|
| $50,000 COGS and $10,000 average inventory | 5.00 turns; 73.00 DSI days | The average item investment is sold and replenished five times. |
| $120,000 COGS, $20,000 beginning and $30,000 ending inventory | 4.80 turns; 76.04 DSI days | The calculator derives a $25,000 average balance. |
| $365,000 COGS and $50,000 average inventory | 7.30 turns; 50.00 DSI days | Annual COGS of $365,000 equals $1,000 per day. |
How to Calculate Inventory Turnover and DSI
- Enter annual cost of goods sold.
- Enter average inventory, or leave it blank and fill beginning and ending inventory instead.
- Select Calculate to see turnover, days sales in inventory, the average inventory used, and daily COGS.
- Compare the DSI figure with the prior period or with a peer that uses the same costing method.
Inventory Turnover Calculator FAQ
Should I use sales or cost of goods sold for inventory turnover?
Use COGS. Inventory is carried at cost, so dividing sales by inventory mixes a retail or wholesale price with a cost-based stock figure and overstates turnover.
How is average inventory calculated if I leave that field blank?
The inventory turnover calculator averages beginning and ending inventory. If you already know a more accurate average from monthly balances, enter that average directly and leave the beginning and ending fields unused.
What is a good inventory turnover ratio?
It depends on the industry and the business model. Grocery and fast fashion turn faster than furniture or industrial equipment. Compare against your own history and close peers rather than a universal target.
Why use 365 days for DSI?
DSI annualizes turnover into days using a 365-day year, a common financial-statement convention. Some analysts use 360 days; pick one convention and keep it when you compare periods.
Can a very high turnover be a problem?
Yes. Extremely high turnover can signal stockouts, lost sales, or a too-thin safety stock. Read turnover next to gross margin and service-level data, not in isolation.