Inventory KPIs turn stock into numbers a team can manage: how fast it sells, how long it sits, how accurate the records are and how often customers get what they ordered. A practical inventory scorecard covers turnover, days of inventory, sell-through, aged and dead stock, inventory accuracy, fill rate, stockout rate, order accuracy and carrying cost. Each needs a formula everyone agrees on, one owner, a target based on your own baseline and a fixed review cadence, weekly for most.
- A KPI only changes behavior when someone owns it, knows what good looks like and sees it on a fixed day every week. Eight or nine owned KPIs get acted on; twenty on a dashboard get ignored.
- Inventory turnover is cost of goods sold ÷ average inventory at cost, and days of inventory is 365 ÷ turnover. Use cost, not retail value, on both sides of the formula.
- Accuracy comes first: aim for 99% or better on inventory accuracy and the high 90s on fill rate. Relaxo runs at 100% inventory accuracy, and Minimalist lifted fill rate from 88% to 98%.
- Across brands in EasyEcom's Festive Report 2025, dead stock fell from 23.2% to 11.7%.
- Report each KPI by channel and by location, not just in total: a strong overall fill rate can hide a marketplace warehouse that runs out every weekend.
- A good weekly inventory report fits on one page and comes from one stock record, not a merge of exports from every channel.
SECTION 01Why inventory KPIs matter
In brief: Inventory KPIs turn stock into numbers a team can manage: how fast it sells, how long it sits, how accurate the records are and how often customers get what they ordered. Tracked weekly with clear owners, they show problems early, before a stockout costs a sale or slow stock becomes a markdown.
Inventory is usually the largest asset an eCommerce brand holds and the one that drifts fastest. Stock sells on one channel and sits on another, records slip away from the shelf, and slow movers age quietly in the back of the warehouse. Without a small set of numbers reviewed on a rhythm, each of those problems is discovered late: at a stockout, a failed count or a year-end write-off.
The key word is small. Twenty KPIs on a dashboard get ignored. Eight or nine, each owned by one person, get acted on.
SECTION 02The inventory KPI scorecard
In brief: A practical inventory scorecard covers turnover, days of inventory, sell-through, aged and dead stock, inventory accuracy, fill rate, stockout rate, order accuracy and carrying cost. Each needs a formula everyone agrees on, one owner, a target based on your own baseline and a fixed review cadence, weekly for most.
| KPI | Formula | Owner | What good looks like | Review |
|---|---|---|---|---|
| Inventory turnover | Cost of goods sold ÷ average inventory at cost | Planning, finance | Rising against your own trend and category; no universal number | Monthly |
| Days of inventory | (Average inventory ÷ cost of goods sold) × 365 | Planning, finance | Close to supplier lead time plus safety stock for steady sellers | Monthly |
| Sell-through rate | Units sold ÷ units received in the period × 100 | Merchandising, planning | Set per season and category; watch the trend week by week | Weekly |
| Aged and dead stock | Value of stock unsold for 90 or more days ÷ total inventory value | Planning, finance | Falling; across brands in EasyEcom's Festive Report 2025 it fell from 23.2% to 11.7% | Monthly |
| Inventory accuracy | Locations or SKUs where system matches shelf ÷ those counted | Warehouse | 99% or better; Relaxo runs at 100% | Weekly |
| Fill rate | Units shipped complete ÷ units ordered | Operations, channel teams | High 90s; Minimalist rose from 88% to 98% | Weekly |
| Stockout rate | SKU-days out of stock ÷ total SKU-days | Planning | Near zero on top sellers; tracked separately for the long tail | Weekly |
| Order accuracy | Orders shipped without error ÷ orders shipped | Warehouse | 99.9%, the level Emiza runs at | Weekly |
| Carrying cost | Annual holding cost ÷ average inventory value | Finance | Known and tracked; lower without hurting fill rate | Quarterly |
Note: Where a real EasyEcom customer result exists, it is shown as a reference point. Where none does, set the target from your own baseline: measure for four to eight weeks, then aim to improve on it.
SECTION 03Inventory turnover and days of inventory
In brief: Inventory turnover is cost of goods sold divided by average inventory at cost: how many times stock sells through in a period. Days of inventory converts that into days: average inventory divided by cost of goods sold, times 365. Higher turnover and fewer days mean less cash tied up, as long as fill rate holds.
Inventory turnover = cost of goods sold ÷ average inventory at cost
Average inventory = (opening inventory + closing inventory) ÷ 2
Days of inventory = (average inventory ÷ cost of goods sold) × 365 = 365 ÷ inventory turnover
Example. A brand's annual cost of goods sold is $2.4 million and its average inventory at cost is $600,000. Turnover is 2.4 million ÷ 600,000 = 4 times a year, and days of inventory is 365 ÷ 4, about 91 days. If the supplier lead time plus safety stock covers 45 days, there is room to hold less.
There is no single good turnover for eCommerce. Fast-moving consumables turn far more often than furniture or jewelry. Compare against your own trend and your category, and look at turnover by SKU group: a healthy overall number often hides a fast-moving head and a stagnant tail. Use cost, not retail value, on both sides of the formula, or the ratio will look better than it is.
SECTION 04Sell-through and aged stock
In brief: Sell-through rate is units sold divided by units received in a period, as a percentage: how much of what you bought has sold. Aged stock is inventory unsold beyond a set number of days, often 90. Together they show which buys are working and which are turning into dead stock before it is too late to act.
Sell-through rate = units sold ÷ units received in the period × 100
Sell-through is the KPI for seasonal and fashion buys. If you received 1,000 units of a new style and sold 400 in its first month, sell-through is 40%. Whether that is good depends on the plan: a style bought for a three-month season is on track; one bought for a two-week promotion is not. Some teams measure against units available, opening stock plus receipts, rather than receipts alone; pick one definition and keep it.
Aged stock is the warning that follows low sell-through. Track the value of stock unsold for 90 days or more, by SKU and location, and give each aged line a decision: promote, bundle, move to another channel or clear. Clearing it earlier costs less than clearing it later. Across brands in EasyEcom's Festive Report 2025, dead stock fell from 23.2% to 11.7%, showing how much discipline here moves the number.
SECTION 05Accuracy and fill rate
In brief: Inventory accuracy measures how often the system matches the shelf; fill rate measures how often customers get everything they ordered. Accuracy comes first, because every other KPI and every channel listing depends on it. In practice, aim for 99% or better on accuracy and the high 90s on fill rate.
- Inventory accuracy is the foundation. If the record is wrong, turnover, days of inventory and reorder points are wrong too. Relaxo reached 100% inventory accuracy and more than 99% bin-level accuracy on EasyEcom; Emiza runs at 99.8% inventory accuracy.
- Cycle-count accuracy shows whether daily counts are finding problems or confirming the record. Minimalist lifted it from 70% to 98.8%. Our guide to cycle counting explains how to set up counts.
- Fill rate is accuracy as the customer sees it. Mindful Souls went from 70% to 100%, Minimalist from 88% to 98%.
- Stockout rate shows where fill rate breaks. Protect top sellers with safety stock and track them apart from the long tail.
- Order accuracy confirms the right item left the building. Emiza runs at 99.9%.
Losses that accuracy work uncovers belong in a shrinkage figure of their own; our guide to inventory shrinkage covers how to measure and reduce it.
SECTION 06Channel-level KPIs
In brief: The same KPIs read differently by channel. Marketplaces punish stockouts with lost ranking, so in-stock rate per listing matters most. Your webstore needs accurate availability and few backorders. Quick commerce measures fill rate per purchase order and days of cover per dark store. B2B measures orders delivered on time and in full.
| Channel | KPIs to add or weight more | Why |
|---|---|---|
| Marketplaces | In-stock rate per listing; cancellations caused by stock; days of cover at marketplace warehouses | Stockouts cost ranking as well as the sale |
| Your webstore | Stockout rate on product pages; backorder rate; available-to-sell accuracy | Shoppers who see "out of stock" leave |
| Quick commerce | Fill rate per purchase order; days of cover per dark store or city | Dark stores replenish every day or two, often with fill-rate penalties |
| B2B and wholesale | Fill rate per order; on-time, in-full delivery | Short or late shipments break the buyer's own plan |
The key is reporting each KPI by channel and by location, not just in total. A strong overall fill rate can hide a marketplace warehouse that runs out every weekend.
SECTION 07Building the weekly inventory report
In brief: A good weekly inventory report fits on one page: headline KPIs against target, exceptions that need action this week, the view by channel and location, accuracy and count results, and a short list of decisions with owners. It should come from one stock record, not a merge of exports from every channel.
- Headline KPIs: the scorecard numbers this week, last week and target, with arrows.
- Exceptions: top sellers at risk of stocking out, SKUs below their reorder point, aged stock crossing 90 days and any SKU with a large count variance.
- By channel and location: fill rate, stockouts and days of cover for each marketplace, the webstore, quick commerce and each warehouse.
- Accuracy: cycle-count results, variances found and fixed, and shrinkage.
- Decisions: reorders to place, transfers to make, stock to promote or clear, each with an owner and a date.
The report is only as reliable as the data behind it. If stock and sales come from separate channel exports, the numbers will disagree before anyone acts on them.
SECTION 08Where EasyEcom fits
In brief: EasyEcom keeps one stock record across every channel and warehouse, synced in 60 seconds, with sales reported by channel and inventory reports that include receiving cost. That gives every KPI on the scorecard one source of truth, so the weekly report shows the business as it is.
EasyEcom's order management system and warehouse management run on one inventory record, synced across every marketplace, storefront and quick-commerce channel in 60 seconds, with channel-wise sales reporting and a full inventory report that carries receiving cost. That is what lets turnover, accuracy, fill rate and aging be measured from the same data rather than reconciled from spreadsheets. For the bigger picture, see our guide to eCommerce inventory management, and for what improving these numbers is worth, our guide to the benefits of inventory management.
Want your inventory scorecard built from one record? Book a demo.
Frequently asked questions
What are the KPIs for inventory management?
The core inventory KPIs are inventory turnover, days of inventory, sell-through rate, aged and dead stock, inventory accuracy, fill rate, stockout rate, order accuracy and carrying cost. Each should have one agreed formula, a named owner, a target based on your baseline and a fixed review cadence, usually weekly.
How do you calculate inventory turnover?
Divide cost of goods sold for the period by average inventory at cost, where average inventory is opening plus closing inventory divided by two. For example, $2.4 million cost of goods sold over $600,000 average inventory is a turnover of 4, meaning stock sold through about four times in the year.
What is a good sell-through rate?
It depends on the product and the period. A seasonal style planned to sell over three months might be on track at 40% after one month, while a two-week promotion should sell through far faster. Set a target for each buy when you place it, then track sell-through weekly against that plan.
What is days of inventory?
Days of inventory, also called days inventory outstanding, is how many days your current stock would last at the recent rate of sale. It is average inventory divided by cost of goods sold, times 365, or simply 365 divided by inventory turnover. Fewer days means less cash tied up in stock.
What should an inventory report include?
A weekly inventory report should show headline KPIs against target, exceptions that need action (stockout risks, SKUs below reorder point, aged stock, large count variances), the view by channel and location, accuracy and count results, and a short list of decisions with owners and dates. One page is enough.
What is the difference between inventory KPIs and inventory metrics?
Every KPI is a metric, but not every metric is a KPI. Inventory metrics are any measurements of stock; inventory KPIs are the few you choose to manage the business by, each with an owner and a target. Keep the KPI list short and leave the rest as supporting metrics.