In-stock rate
In-stock rate is the share of store-product combinations that should be on sale and have saleable stock at the time of measurement; it shows how likely a shopper is to find the item.
Also calledon-shelf availability, OSA, in-stock percentage, product availability, stock availability rate
Formula
(Active store-product combinations − Out-of-stock combinations) ÷ Active store-product combinations × 100- Active store-product combination
- Every product that should be on sale in a store's range; out-of-season and delisted products excluded.
- Out-of-stock combination
- A combination with zero saleable stock at the time of measurement.
- Out-of-stock rate
- 100 − In-stock rate.
Calculator
Enter your own figures and the result updates instantly. The defaults are the figures from the worked example below.
Result%93,5
Worked example
How to read it, and what good looks like
In-stock rate is the precondition for sales: a product that is not on the shelf does not sell, and that loss appears in no sales report. International measurements show how large the loss is; the GMA (2002) and Corsten and Gruen (2004) figures in the benchmark table are there for that. There is no recent public measurement for Turkey, so the target is built from the chain's own history.
Measuring on system stock misses goods that appear in the records but are not on the shelf (phantom stock); if inventory record accuracy is low, the in-stock rate looks better than it is. The cheapest signal is in the sales data: if a product that normally sells steadily shows zero sales for several days while system stock is positive, it is very likely not on the shelf. Track promotions separately; according to ECR Europe's 2003 study, out-of-stocks on promoted items run at about twice the rate of regular items.
The target is not a single number; it is set by product group. Best sellers and promoted lines get a high target, the long tail a lower one, and the target is set together with the cost of safety stock and your own quarterly history. In Mindpera, Mind Send raises a replenishment proposal for any store that drops below threshold and shows, in the unmet demand report, which product ran short in which store; Mind Stock tracks record accuracy through count variance analysis.
| Context | Value | Note |
|---|---|---|
| On-shelf out-of-stock rate, global average (GMA 2002) | 8.3% | Europe 8.6%; 29 countries, over 71,000 shoppers. Cited by Pygmalios 2026. |
| Sales lost to stock-outs, FMCG (HBR 2004) | About 4% of sales | Corsten and Gruen; cited by Pygmalios 2026. |
Where it misleads
- Without a written active range, out-of-season products enter the denominator and the rate looks low; dropping out-of-stock products from the range inflates it artificially.
- Measuring on system stock misses phantom stock; in a store with poor record accuracy the in-stock rate comes out optimistic.
- A close-of-day measurement misses a shelf that empties during the day and is refilled in the evening; measure fast sellers intraday.
- The chain average hides gaps on best sellers; report the rate by product group and store.
Data you need
- Active range by store, with delisting dates
- Daily or hourly stock balance by store and product
- Sales lines, for rate of sale and the zero-sales signal
- Shelf audit records and the promotion calendar
Mindpera products that calculate this KPI
Mind Send
Make your shipments manageable. Depot-to-branch dispatch, branch-to-branch transfer and the initial allocation decision are produced together with the demand forecast.
Mind Stock
Stop treating stock accuracy as something that waits for a count and a month-end close. See movements in and out, expiry dates and profitability on one screen.
Frequently asked questions
- How do you calculate in-stock rate?
- Divide the number of store-product combinations with stock by all combinations that should be on sale, and multiply by 100. If 1,560 of 24,000 active combinations have no stock, the in-stock rate is (24,000 − 1,560) ÷ 24,000 × 100 = 93.5%. The active range must be written down; out-of-season products stay out of the denominator. Report the result by product group and store.
- What is a good in-stock rate?
- Set the target by product group: high for best sellers and promoted lines, lower for the long tail. For context, GMA's 2002 global study put the average on-shelf out-of-stock rate at 8.3%, meaning average availability of around 92%. Set the target together with the cost of safety stock and your own quarterly history.
- Why is a product missing from the shelf when the system shows stock?
- The record and the physical position have diverged: the item is stuck in the stockroom, lost, sold under the wrong barcode or received incorrectly. This is phantom stock, and it makes an in-stock rate measured on system stock look better than it is. Send products with positive system stock but several days of zero sales for a shelf check; the lasting fix is better record accuracy.