Pareto Analysis Calculator
Rank up to ten categories by count with shares and cumulative share.
In short
Rank up to ten categories by count with shares and cumulative share.
Formula: Share_i = (Count_i ÷ Σ Count) × 100; Cumulative_i = (Σ_{j≤i} Count_j ÷ Σ Count) × 100, categories sorted from largest to smallest
What this calculator does
Sort descending, divide each count by the total, accumulate. The number of categories making up the first 80% is reported as a reading aid.
Use it to turn Category 1, Count 1, Category 2, Count 2, and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Category 1
- — text value.
- Count 1
- — Defects, complaints, downtime minutes or cost — one consistent measure across all categories..
- Category 2
- — text value.
- Count 2
- — Defects, complaints, downtime minutes or cost — one consistent measure across all categories..
- Category 3 (optional)
- — text value.
- Count 3 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 4 (optional)
- — text value.
- Count 4 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 5 (optional)
- — text value.
- Count 5 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 6 (optional)
- — text value.
- Count 6 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 7 (optional)
- — text value.
- Count 7 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 8 (optional)
- — text value.
- Count 8 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 9 (optional)
- — text value.
- Count 9 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
- Category 10 (optional)
- — text value.
- Count 10 (optional)
- — Optional. Leave at 0 to exclude it from the result. A category counted as 0 is left out of the chart..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
Share_i = (Count_i ÷ Σ Count) × 100; Cumulative_i = (Σ_{j≤i} Count_j ÷ Σ Count) × 100, categories sorted from largest to smallest.
Inputs used: Category 1, Count 1, Category 2, Count 2, Category 3 (optional), Count 3 (optional), Category 4 (optional), Count 4 (optional), and other shown inputs.
Edge handling: Count 1 is required.; Count 1 cannot be negative.; Count 1 must be no more than 1000000000000.; Count 2 is required.; Count 2 cannot be negative..
Worked example
Five defect categories ranked
- Start with Category 1: Surface scratches, Count 1: 120, Category 2: Dimensional out of tolerance, Count 2: 64, Category 3 (optional): Missing fastener, Count 3 (optional): 38.
- Apply the method: Share_i = (Count_i ÷ Σ Count) × 100; Cumulative_i = (Σ_{j≤i} Count_j ÷ Σ Count) × 100, categories sorted from largest to smallest.
- Ranked by count, with each category's share and the running cumulative share.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this pareto analysis calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: American Society for Quality — Process capability and defect rate measures
Last reviewed:
Common questions
Where does this formula come from?
ASQ quality resources, Pareto chart: categories are ordered by frequency with a cumulative percentage line. See the source link on this page.
What kind of calculation is this?
Categories are sorted by count, each share is expressed against the total, and the cumulative share is accumulated down the ranking. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
Ranking by count treats every occurrence as equally important; a rare but severe category will rank low. The result depends entirely on how the categories were defined. Arithmetic over the counts entered — it cannot tell whether the inspection behind them was complete or consistent.
How do I use the Pareto Analysis Calculator?
Enter the required values for Category 1, Count 1, Category 2, Count 2, Category 3 (optional), and the other fields shown. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Pareto Analysis Calculator use?
Share_i = (Count_i ÷ Σ Count) × 100; Cumulative_i = (Σ_{j≤i} Count_j ÷ Σ Count) × 100, categories sorted from largest to smallest The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the Pareto Analysis Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
Categories are sorted by count, each share is expressed against the total, and the cumulative share is accumulated down the ranking.
The question it answers: How much of our output is right first time, and how much survives every step?
The formula
Share_i = (Count_i ÷ Σ Count) × 100; Cumulative_i = (Σ_{j≤i} Count_j ÷ Σ Count) × 100, categories sorted from largest to smallest
- Count_i — Category count
- (count). Defects, complaints, downtime or cost for one category — one consistent measure across all categories.
- Σ Count — Total
- (count). Sum of the categories entered.
Units: One consistent measure in; percentages out.
What kind of calculation this is
Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.
Method
Sort descending, divide each count by the total, accumulate. The number of categories making up the first 80% is reported as a reading aid.
Assumptions built into the result
- Mathematical: All categories are measured on the same scale.
- Mathematical: Categories do not overlap.
Figures this calculator will never guess for you
- No benchmark, target or 'world class' value is supplied or implied; the result describes only the figures entered.
- The 80/20 pattern is not assumed — the cumulative share is reported from the entered counts, whatever it turns out to be.
- No cause, priority or corrective action is inferred from the ranking.
Limitations
- Ranking by count treats every occurrence as equally important; a rare but severe category will rank low.
- The result depends entirely on how the categories were defined.
- Arithmetic over the counts entered — it cannot tell whether the inspection behind them was complete or consistent.
Source and version
- Standard or reference
- Pareto chart — ASQ (ASQ quality resources, Pareto chart: categories are ordered by frequency with a cumulative percentage line.)
- Published source
- American Society for Quality — Quality resources
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Standards or government
- Applies to
- Currency
- The result is a ratio or index, so it does not depend on currency.
Cite this page
Free Calculator. (2026, September 16). Pareto Analysis Calculator. https://freecalculator.tech/tools/pareto-analysis-calculator
"Pareto Analysis Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/pareto-analysis-calculator.
Pareto Analysis Calculator — Free Calculator, https://freecalculator.tech/tools/pareto-analysis-calculator
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