Compare three variables with a bubble chart.

How to use this bubble chart tool

This free bubble chart maker adds a size dimension to a scatter plot. Each row becomes one bubble: its horizontal and vertical positions come from two numeric variables, while its area represents a third numeric measure.

1. Import four useful columns

Select Import data to upload a CSV, TSV, TXT, JSON, XLSX, or XLS file, or paste comma-separated data. Choose a label column plus numeric X, Y, and size columns. A preview lets you verify the mapping and exclude rows before the chart changes.

2. Review and edit every bubble

Use the editable table to correct labels or values, add and remove bubbles, reverse the order, or sort any column. Size values must be zero or greater; the tool scales valid values into a readable minimum and maximum radius.

3. Tune the visual encoding

Choose the fill and border colors, bubble opacity, size range, title, and axis labels. Optional point labels are useful for smaller datasets, while tooltips keep denser charts readable. Zoom and pan along the X axis when observations overlap.

4. Export the finished chart

Download a PNG for reports and presentations or an SVG for scalable layouts. Select the output dimensions, aspect ratio, render scale, and background transparency in the export preview.

How to read a bubble chart

Read the chart in three passes: compare left-to-right position on the X axis, bottom-to-top position on the Y axis, and then bubble area. Nearby bubbles have similar X and Y values; larger bubbles represent more of the size measure.

Compare area, not diameter

A bubble chart should scale circle area to the underlying value. This tool uses square-root scaling so a value four times larger produces a circle with four times the area—not four times the diameter.

Keep labels, units, and scales explicit

Name all three measures in the title, axis labels, or surrounding text. Avoid using negative size values, explain the size unit, and investigate unusually large bubbles before drawing conclusions from the pattern.

Practical example: compare products on three measures

A product portfolio can place price on the X axis, customer rating on the Y axis, and annual sales in bubble area. This view helps identify high-rated products, crowded price ranges, and commercially important outliers in one chart. It does not combine the measures into a score: each visual channel retains its own meaning, so readers can decide which tradeoff matters.

Prevent large bubbles from hiding the data

Area encoding can cause a few high values to cover smaller observations. Reduce the maximum bubble size, lower fill opacity, enable outlines, or zoom into a crowded region. If the size measure is not central to the question, a simpler scatter plot will often be easier to interpret.

Check comparability before drawing a conclusion

All rows should describe the same type of entity and measurement period. Currency should use a common basis, ratings should share a scale, and size values should be non-negative. Explain whether a missing row was excluded, and avoid treating proximity or bubble size as proof that one variable caused another.