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Pareto chart maker

Paste your data from Excel and see in seconds which few categories account for most of the defects, stoppages or costs — with the chart ready to download.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

CheckRevised 11/03/2026
Data
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Accepts semicolons, tabs (Excel) and decimal commas. Repeated categories are added up; with no number, each line counts as 1 (paste the defect log directly, one per line). The 1st line can be a header. Changing the layout also swaps the example.

Chart

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—Vital few
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Pareto chart

Bars from largest to smallest, cumulative percentage curve (right axis) and cut-off line. The vertical line marks off the vital few.

Tap the chart to see the values.

Tap the chart to see the values.

How to read: each bar is a category, from largest to smallest; the height is the count (left axis). The curve climbs as it adds the bars up to 100% (right axis). The bars to the left of the vertical line are the vital few: tackling only them solves most of the problem. Bars all about the same height = no vital few; stratify.

Pareto table

Every category in order, with count, percentage and cumulative percentage. Download as .xlsx with the button at the end of the page.

Next step

Take this page’s results to another calculator with the fields already filled in.

The calculation report gathers this page's inputs, results, equations, assumptions and references, with fields for project, engineer and revision. The full report also includes the charts and interpretations, in color. In the print dialog, choose Save as PDF.

Method, assumptions and references

Equations used

Categories in decreasing order of count; % = count ÷ total; cumulative % = sum of % up to the category
Vital few = smallest number k of categories whose cumulative % ≥ cut-off (80% by default); “Other” always goes last and does not count toward k
Weighted Pareto: value = Σ (count × unit cost or weight) per category
Before vs after: reduction = 1 − total after ÷ total before; both charts use the same vertical scale

Assumptions and limits

  • In the main chart the left axis runs from 0 to the total, so the cumulative curve (right axis, 0–100%) lines up with the bars, as in Juran’s Pareto.
  • Categories with the same name (ignoring case and accents) are added together. Rows with no number count as 1. A category named “Other” goes into the “Other” bar.
  • The Pareto shows frequency or cost, not cause: the 1st bar is the problem to investigate; the cause is found afterwards (fishbone, stratification, data).

Standards and technical documents

  • Juran, J. M. Quality Control Handbook. McGraw-Hill, 1951 (Pareto principle, vital few)
  • Ishikawa, K. Guide to Quality Control. Asian Productivity Organization, 1976 (cap. 5, Pareto diagrams)
  • Montgomery, D. C. Introduction to Statistical Quality Control, 8th ed. Wiley, 2019 (seção 5.4, the magnificent seven)
  • Tague, N. R. The Quality Toolbox, 2nd ed. ASQ Quality Press, 2005 (Pareto chart, weighted Pareto)
  • ISO/TR 10017:2003 Guidance on statistical techniques for ISO 9001:2000 (Pareto analysis)

U.S. regulations

  • ISO 9001:2015, 9.1.3: analysis and evaluation
  • ISO 9001:2015, 10.2: nonconformity and corrective action

Frequently asked questions

How do I make a Pareto chart?

List the categories (defect types, stoppage reasons) with the count for each, sort from largest to smallest, and work out each one’s percentage and the cumulative percentage. Bars show the counts and the line shows the cumulative total. Here you just paste the two columns from Excel: the sorting, percentages and chart come out ready.

How do I read a Pareto chart?

Look at where the cumulative curve crosses the 80% line: the bars to the left of that point are the vital few, which deserve action first. Then check the size of “Other” — if it is large, the classification is too generic. Bars of almost the same height mean there is no clear priority.

Is the 80/20 rule always true?

No. It is a guideline for concentration, not a law. Sometimes 2 categories make up 90%, sometimes it takes 6 to reach 80%. When the chart comes out flat, stratify the data (by shift, machine, product) or weight it by cost: the concentration usually shows up.

Can I paste the defect list without counting?

Yes. Paste the log with one occurrence per line (for example, the “defect” column of the inspection sheet): each line counts as 1 and the page adds up repeats, ignoring case and accents. It handles tens of thousands of lines.

When should I use a Pareto by cost?

When defects cost very different amounts: a dent that turns into scrap can cost ten times more than a scratch that only needs polishing. Choose the layout with cost and see both Paretos side by side; if the order changes, prioritize by cost and use frequency to guide data collection.

What is a before vs after Pareto for?

To show the effect of an improvement action. Both charts are drawn on the same scale: the targeted bar should shrink, and so should the total. The page calculates the reduction and shows which category became the 1st — the next priority.

How do I download the chart?

The “Download PNG” button creates a high-resolution image on a white background, ready for a presentation or an A3 report. The “One-page report (PDF)” has the chart, the vital few and the conclusion, and the .xlsx button downloads the full table.