Rank inventory by economic importance and automatically classify items into A, B and C groups. Use annual consumption value or import a direct ranking value such as revenue or gross margin.
Standard ABC analysis ranks items by value contribution. The default thresholds classify items until cumulative value reaches about 80% for A and 95% for A plus B. You can change these cutoffs to match your inventory policy.
Classification settings
Item data
| SKU | Item Name | Annual Usage | Unit Cost | Direct Annual Value | Remove |
|---|
ABC Analysis Results
Classification completePareto Distribution
| Rank | Class | SKU | Item | Annual Usage | Unit Cost | Ranked Value | Value Share | Cumulative Value | Cumulative SKUs |
|---|
A Items: Tight Control
Prioritize forecasting, supplier reliability, frequent review, cycle counting and carefully designed safety stock.
B Items: Balanced Control
Use regular review intervals, standard reorder policies and moderate management attention.
C Items: Simplified Control
Reduce administrative effort with simpler replenishment rules while checking for obsolete or strategically critical items.
ABC analysis sorts inventory by economic weight — the idea being that a handful of items usually matter far more than the rest, so they deserve more of your attention than everything else combined.
WareStat’s ABC Analysis Calculator ranks your SKUs automatically, works out cumulative value contribution, and slots each item into Class A, B or C. Type products in by hand, paste a spreadsheet, or import a CSV — whatever’s easiest.
How It Actually Works
The traditional method ranks by annual consumption value:
Annual Consumption Value = Annual Usage × Unit Cost
From there:
- rank everything highest to lowest
- compare each product against total portfolio value
- turn that into cumulative percentages
- sort into A, B or C
A common starting split looks like this:
A items — roughly the first 80% of cumulative value B items — the next stretch, 80% to 95% C items — whatever’s left
Guidelines, not gospel — which is why WareStat lets you move both thresholds wherever your actual data suggests they should sit.
A Small Worked Example
Three products. Annual consumption values of $50,000, $30,000 and $20,000 — call them A, B and C. Total value: $100,000.
Product A alone is half the total. Add Product B and you’re already at 80% cumulative. Under an 80% A-threshold, both A and B land in the top priority tier — leaving C on its own, way down at the bottom.
That’s the math for three products. Import a few hundred SKUs and the calculator does the identical thing automatically — no spreadsheet gymnastics required on your end.
What A, B and C Actually Mean
A items carry the most economic weight, and that usually earns them tighter control — frequent review, real demand planning, suppliers you can actually count on, cycle counting, safety stock that’s been properly calculated rather than guessed at.
B items sit in the middle. Regular monitoring, standard replenishment rules. Nothing that needs the same hands-on attention as Class A, but not something to ignore either.
C items contribute comparatively little to total ranked value, so simpler rules and less frequent review make sense here — it just isn’t worth the administrative overhead of treating a C item like an A item.
One catch, though: ABC classification measures economic contribution, full stop — not how badly production grinds to a halt without it. A cheap component that happens to stop the whole line if it’s missing doesn’t deserve a C-item level of neglect just because the math says C.
Consumption Value Isn’t the Only Option
Classic ABC ranks by:
Annual Usage × Unit Cost
But WareStat also has a Direct Annual Value mode, which lets you run the exact same Pareto process against a different metric entirely — annual revenue, gross margin contribution, purchasing value, forecast consumption value, whatever fits what you’re actually trying to optimize.
Just keep it consistent. Whatever metric you pick, use it for every single SKU in that analysis — mixing metrics partway through defeats the whole point.
Reading the Pareto Chart
The chart plots cumulative portfolio value against cumulative percentage of SKUs. A steep curve near the start means a small slice of your catalog is doing most of the economic work.
WareStat also breaks out a few extra numbers alongside the chart: value generated by your top 20% of SKUs, the share of products actually classified A, and how much the single largest item contributes on its own. Useful, because not every business follows a textbook 80/20 split — some are far more concentrated, some far flatter — and these numbers tell you which one you’re looking at instead of you having to assume.
About That 80/15/5 Split
It’s a starting point. Not a law of nature.
A tightly concentrated product line might hit 80% of value with just a handful of SKUs. A more evenly spread assortment might need far more products to get there. Both are normal — they just call for different thresholds.
Which is why the calculator ships with 80/95, 70/90 and 75/95 presets, plus fully custom thresholds if none of those fit.
Turning Classification Into Policy
ABC only earns its keep once each category actually changes what you do.
A items, for example, might get tighter safety-stock math and more frequent review. B items run on standard reorder policies. C items can lean on simple Min/Max rules or get bought in bulk without much fuss.
In other words: the classification is where inventory optimization starts, not where it ends.
FAQ
What does ABC analysis mean in inventory management? It ranks items by their contribution to a chosen value metric, then splits them into high-, medium- and lower-priority groups.
What’s the formula for ABC inventory analysis? Annual Usage × Unit Cost, ranked, then divided against total portfolio value and accumulated top to bottom.
Are the percentages always 80/15/5? No — that’s just a common starting point. The right thresholds depend on how your own portfolio is actually distributed, and what you’re trying to achieve with the analysis.
Can I import from Excel? Yes, either way — copy rows straight in, or save as CSV and import the file.
Can I rank by sales revenue instead of inventory cost? Yes. Switch to Direct Annual Value and apply revenue consistently across every item. Just know that’s a revenue-based classification, not the traditional consumption-value version.
How often should this be redone? Whenever demand, costs or the product mix shift in a real way. Leave a stale classification running long enough and it’ll start pointing you toward the wrong products entirely.