Inventory turns / year
7.29
Free calculator
Type your average inventory value and annual cost of goods sold. Days inventory outstanding updates as you type. No email, no gate, nothing leaves this page.
The calculator
The boxes start filled with an illustrative example, not a benchmark. Replace it with your own numbers. Both figures should cover the same twelve-month period.
The average value of inventory on hand across the period. A common simple method: (starting inventory + ending inventory) / 2.
Cost of goods sold for the same twelve-month period, not revenue.
Days inventory outstanding
At this average inventory value and this annual COGS, stock sits for about 50.0 days before it turns over, on average.
days inventory outstanding = average inventory value / annual COGS × 365 inventory turns / year = 365 / days inventory outstanding average daily COGS = annual COGS / 365
Days inventory outstanding and inventory turnover are the same underlying ratio, viewed two ways: turnover = 365 / DIO. That calculator is here.
See it on your own data Real numbers from your Shopify store, not a guess.
This uses one average inventory figure for the whole period. A business with a sharp seasonal peak, a holiday build-up followed by a slow stretch, can show a DIO that looks perfectly fine on average while actually sitting on months of dead stock right after the peak. Averaging smooths that entirely away.
The same is true in reverse: a business that runs lean most of the year but stocks up hard right before the measurement date can look worse than it really is. One blended number for a full year cannot see either pattern. It can only tell you the average, not the shape of the year underneath it.
Questions
It is the average number of days between buying or making inventory and selling it, based on your average inventory value and your annual cost of goods sold. A lower number means stock moves faster on average; a higher number means it sits longer before it sells.
There is no universal healthy number. It depends heavily on category: fast-moving consumer goods and perishables often run in the days to a few weeks, while furniture, jewelry, and other considered purchases can run to several months and still be entirely normal for that category. Compare your own DIO against your own history and your own category, not against a generic benchmark.
They are the reciprocal of the same underlying ratio, not two independent measurements. Turnover tells you how many times a year you sell through stock; DIO tells you how many days that represents. The formula that connects them is 365 / turnover = DIO. The inventory turnover calculator uses the same two inputs and lands on the same relationship from the other direction.
Conceptually, only two levers move it: sell through stock faster, or hold less inventory relative to what you sell. What actually drives either of those, better demand forecasting, tighter reorder points, clearing slow SKUs, is a business decision this calculator does not make for you. It only shows you where the ratio sits today.
That depends entirely on how you define "average inventory" when you calculate it, not on the DIO formula itself. Some businesses count inventory in transit as owned stock the moment it ships from the supplier; others only count it once it lands in a warehouse. Be consistent about which definition you use, since it changes the input, not the math.
Next
Upstream reads real per-SKU cost and real inventory movement straight from your store, so you can see which products are actually sitting, not just one blended average across everything you sell. It is the connected version of the calculator above.