Free tool

Pareto chart generator

Paste your downtime reasons, defect types or cost items with their values; get a sorted Pareto chart, the cumulative percentage and the few causes to tackle first.

Result

Pareto chart

Vital few (up to the 80 % line)
Others
Cumulative %

Sorted table

What a Pareto chart shows

A Pareto chart sorts the causes of a problem from largest to smallest so you can see which few causes make up most of the total. J. M. Juran named the idea the "vital few" in quality management; the name comes from the economist Vilfredo Pareto, who studied the distribution of income. The bars show the value of each cause and the line shows the cumulative percentage.

The example in the tool is one week of downtime on a moulding line, in minutes. Total downtime is 870 min; the first 4 causes (mould change 310 min, waiting for material 185 min, hydraulic breakdown 140 min, set-up and trial shots 95 min) make up 83.9 % of the total. The cumulative shares are 35.6 %, 56.9 %, 73.0 % and 83.9 %. Focusing on half of the 8 causes targets more than 80 % of the downtime, and since mould change is the largest item, the first step is often a SMED study.

How the calculation works

Categories written more than once under the same name are merged and their values added.
Categories are sorted by value from largest to smallest (equal values keep the order you entered).
Share = category value / total; cumulative share = sum of the values up to that category / total.
Categories until the cumulative share reaches 80 %, including the one that crosses 80 %, are marked as the vital few.

80 % is a convention, not a statistical limit. When you set priorities, also weigh the cost of the fix, safety and the effect on customers.

For a useful Pareto

Standardise the categories: if the same cause is written in different words, its value is split and the ranking misleads. Use a fixed list of downtime and defect reasons.
Keep "Other" small: if "Other" climbs to the top, the categories are defined too broadly.
Choose the right measure: count, time and cost can give different rankings; time or cost is usually more meaningful for decisions.
Compare before and after: after an improvement, draw a new Pareto over a period of the same length; the largest bar should have shrunk and the order changed.

Export to Excel

"Download CSV" saves the rank, category, value, share and cumulative percentage as a comma-separated file with dot decimals. Excel 2016 and later can also draw a Pareto chart from Insert > Insert Statistic Chart. To put a cost on the downtime minutes, use the downtime cost calculator; all tools are on the tools page.

From counting downtime by hand to collecting it automatically

When downtime is collected from the machine and the operator picks the reason on a screen, the Pareto updates every shift and the categories are standard from the start. We describe how on our downtime tracking page.

Source: J. M. Juran, Juran's Quality Handbook (the Pareto principle, "vital few and useful many"). Checked 24 October 2026.

Frequently asked questions

Common questions

How do you make a Pareto chart?

Group the problems by cause and add up a value for each cause (count, minutes, cost). Sort the causes from largest to smallest and work out each one's share of the total and the cumulative share. The causes up to the point where the cumulative share reaches 80 % are the "vital few", where improvement starts. The generator does every step with your data.

Is the 80/20 rule exact?

No. 80/20 is a convention for remembering Juran's "vital few" principle. In real data the top 20 % of categories may account for 60 % of the total or for 95 %. The 80 % line in the tool is a reference; the category that crosses it is counted among the vital few.

How do I make a Pareto chart in Excel?

In Excel 2016 and later, select the data and choose Insert > Insert Statistic Chart > Pareto. In older versions, sort the data from largest to smallest, add a cumulative percentage column and combine a column chart with a line on a secondary axis. This tool's "Download CSV" gives you rank, share and cumulative percentage ready for Excel.

Should I use frequency or cost?

They can give different priorities. A frequent but cheap defect may matter less than a rare but expensive breakdown. Where you can, draw both a count and a minutes or cost Pareto from the same data; for decisions, time or cost is usually more meaningful.

What if I write the same cause differently?

Names that differ only in capitals or spacing (for example "Mould change" and "mould CHANGE") are treated as one category, their values are added and the tool lists which names were merged. Causes written with different words ("mould change" and "die change") cannot be merged automatically; standardise the category names first.