Free tool
80/20 calculator
Does your data actually follow the 80/20 rule? See what the top 20% of categories contributes, and which categories carry the weight.
Calculations run in your browser. Saving uploads the analysis; asking AI sends its data for processing.
CSV, TSV or pasted spreadsheet cells. Delimiter detected automatically (7 data rows).
Saving supports up to 500 input rows. Duplicate labels are combined in the result.
Preview the first 20 usable rows
80/20 analysis
- Total
- 5,300
- Categories
- 7
- Vital few
- 3
- Top 20% share
- 66%
Priority #1
Login failures
39.62% of total · 2,100
| # | Category | Value | Share | Cumulative |
|---|---|---|---|---|
| 1 | Login failures Vital few | 2,100 | 39.62% | 39.62% |
| 2 | Payment errors Vital few | 1,400 | 26.42% | 66.04% |
| 3 | Performance Vital few | 800 | 15.09% | 81.13% |
| 4 | Billing questions | 400 | 7.55% | 88.68% |
| 5 | Email delivery | 300 | 5.66% | 94.34% |
| 6 | Feature requests | 180 | 3.4% | 97.74% |
| 7 | Other | 120 | 2.26% | 100% |
3 of 7 categories account for 81.1% of total impact.
Vital few: Login failures, Payment errors, Performance.
Login failures is the largest contributor at 39.62%.
Login failures represents 2,100 of a total of 5,300.
Moderate concentration: the top 20% of categories hold 66%.
There is a leading group, but the long tail still matters.
4 categories share the remaining 18.9%.
These are the trivial many under the Pareto principle.
Review Login failures first.
It is the single largest contributor at 39.62% of total impact.
Review opportunities across the wider process.
Impact is spread out — the top 20% only accounts for 66%.
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About the 80/20 rule
The Pareto principle says roughly 80% of outcomes come from 20% of causes. Real data rarely lands on exactly 80/20 — it might be 70/30 or 95/5. What matters is the shape: the more concentrated your data, the more a focused effort pays off.
Go deeper with the full Pareto analysis.