Inventory accuracy calculator
Count one shelf without looking at what your records say, then type two numbers. You get your record accuracy, the working, and what the one published study of real stores found.
StockRoom works it out after every count
Count hides what your records say while you count, then shows the share that were right beside this research, and writes every difference as an adjustment with your name on it.
Free up to 50 products, then A$9 a month. No card to start. No account yet? The free stock count does it line by line in your browser.
The inventory accuracy formula
Record accuracy = records exactly right ÷ records counted × 100
A record is one product in one place. It is right when your count and the record agree to the unit. Leave out anything you did not reach: an uncounted product is neither right nor wrong. A record that says none, where there are none, is right.
Accuracy by units is a different number. Five products, four of them out by one, can be 107 of 111 units right and still only 20% of records right. Both are true. The research measures records, because one wrong record is one product you cannot trust.
What the research found
The one published measurement of real stores is by Raman, DeHoratius and Ton, in Execution: the missing link in retail operations (2001). They looked inside leading retailers in confidence and found records right for 35% to 65% of products at store level. At one retailer the wrong records cost about a tenth of its profit; at another, products in the wrong place cut profit by a quarter.
What drove the errors: how stock was replenished and sold, how it was merchandised, and staff turnover. What helped: counting a little and often, training, carrying fewer variations of each product, and measuring against others.
It was published in 2001, it is large chains, and nobody has published the same measurement for small shops. Read it as a rough mark, not a target. The 95% to 99% you will see on software sellers' pages are what warehouses aim for, not what stores were found to have.
Source: the University of Arkansas CELDi project summary, Improving Inventory Record Accuracy within Retail Store Operations, read 26 September 2026.
Measure yours in ten minutes
- Pick one shelf or bay.
- List what is on it without the quantities. The stock count sheet prints one.
- Count every product, without looking at your records.
- Compare each count with what the records say.
- Divide the ones that matched by the ones you counted.
Then fix each difference with a reason, and count the same shelf again in a month. The second number is the one that tells you whether anything changed.
Questions people actually ask
What is the inventory accuracy formula?
Records exactly right, divided by records counted, times 100. Count one place, compare each product's count with what your records say, and only a product that agrees to the unit counts as right.
What is a good inventory accuracy?
The one published study of real stores found 35% to 65% of records right at well-known retailers, in 2001. Warehouses that count often aim for 95% and above. Nobody has published a figure for small shops, so your first count is your baseline: count the same place in a month and see whether it moved.
Why count without looking at the records?
Somebody who can see "should be 12" tends to count twelve. Hiding what the records say is what makes the count a test of the records rather than of the person counting.
Why does my stock never match the system?
The study put it down to how stock is replenished and sold, how it is merchandised, and staff turnover. A short count is very often stock sitting in another place, so check every other place before you adjust a short one.
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