Understanding your result
Turnover is a ratio for the period you entered, not automatically an annual rate. Days held divides the period length by turnover. A zero cost of goods sold produces zero turns and an undefined days figure rather than a fictitious finite holding time.
For the fraction of a received batch sold, use the Sell-Through Rate Calculator which measures physical units rather than accounting values.
The formula
The two-balance average is a simple approximation of inventory held during the period. Use the same currency and valuation basis throughout. Sales revenue is not substituted for cost of goods sold because retail markups would make that numerator inconsistent with stock valued at cost.
Worked example
Cost of goods sold of 120,000 and balances of 20,000 and 28,000 give average inventory of 24,000. Turnover is 5 times. Across 365 days, that corresponds to 73 days held. The same ratio over a 90-day period would correspond to 18 days.
How to use this calculator
- Enter period cost of goods sold for the stock being measured.
- Enter opening and closing inventory values at cost in the same currency.
- Set the number of days and review the ratio together with days held.
Match the scope before comparing
An entire store’s cost of goods sold should not be divided by one department’s inventory. Similarly, a quarter’s numerator should use balances and days for that quarter. Keep the valuation method and product population consistent when comparing periods; an apparent improvement can otherwise come from a reporting change.
Seasonal stock can defeat a two-point average
Two endpoint balances may miss a large purchase and clearance inside the period. Monthly or daily average balances can better represent a seasonal business, but this tool deliberately uses the displayed opening-and-closing formula. Treat the result as an approximation when stock fluctuates sharply.
High turnover is not automatically a better outcome
A rapid stock cycle can accompany good demand, but it can also accompany insufficient stock. Review availability, margins, and customer service alongside turnover. There is no universal target embedded here. Days held is an accounting ratio, not a forecast of the exact day a specific batch will sell.
Assumptions & limitations
What this calculation assumes
- Opening and closing balances reasonably approximate average inventory.
What to keep in mind
- Does not reconcile inventory valuation, returns, write-downs, or missing cost records.
Common questions
Should I enter sales revenue?
Use cost of goods sold. Sales revenue includes markup and does not match stock valued at cost.
Is days held the same as future stock cover?
No. This result uses period cost flows and average inventory. Future stock cover would compare current units with expected demand.