How to make a polar area chart
- Enter your categories in order, for example the 12 months, one per row.
- Enter each category’s value. Values must be zero or positive.
- Choose the value encoding in Customize → Chart options. Area-proportional is recommended.
- Set the start angle, toggle category and value labels, and pick a palette.
- Download as PNG, SVG or PDF.
Data format
| Column | Type | Notes |
|---|---|---|
| Category | Text | Required |
| Value | Number (zero or positive) | Required |
Up to 60 rows. One row per segment. Every segment gets an equal angle; the value sets how far it extends from the center.
Customization options
- Area-proportional or radius-proportional scaling.
- Start angle so January (or midnight) sits at the top.
- Circular gridlines with value labels.
- Category labels around the edge and optional value labels inside segments.
- Per-segment colors and pattern fills.
Downloading and exporting
- PNG: best for slides, documents and the web. It supports transparent backgrounds, and you can choose standard, 2×, 4× or slide-sized (1920 × 1080) output.
- JPEG: a smaller file with a solid background.
- SVG: a true vector file. It stays sharp at any size and can be edited in Illustrator, Inkscape or Figma.
- PDF: vector PDF sized to the chart, A4 or US Letter. If your labels use characters outside the standard PDF fonts (for example Chinese, Arabic or emoji), the PDF uses a high-resolution image instead and tells you.
- CSV and .json: your data, or the whole chart with its settings, to re-open later.
When to use a polar area chart
- Cyclical data where the circular layout is meaningful: months, days of the week, hours, compass directions.
- Eye-catching summaries for infographics, where the exact values are also given in labels.
When to choose a different chart
- The categories are parts of a whole. A pie chart is the standard form.
- Exact comparison matters. A bar graph is easier to read.
- Several criteria per item. Use a radar chart.
Common mistakes to avoid
Radius scaling that exaggerates
Because segments are wedges, doubling the radius quadruples the area. The default area-proportional setting avoids this distortion.
Treating it like a pie
Segment angles are all equal and carry no meaning. Values are encoded by how far each segment reaches.
Arbitrary category order
The circular layout implies a cycle. If your categories have no natural order, a bar chart is more honest.
Practical examples
Seasonal demand
Average daily bike rentals by month, showing the summer peak.
Wind directions
Number of days the wind blew from each of 8 compass directions.
Hourly activity
Website visits by hour of day, starting at midnight at the top.
Florence Nightingale’s “coxcomb”
The polar area chart is associated with Florence Nightingale’s 1858 diagrams of mortality in the Crimean War, which showed that preventable disease killed far more soldiers than battle wounds did. Her diagrams sized wedges so that their area represented the number of deaths. This tool’s default “area proportional” scaling follows the same principle: the radius grows with the square root of the value.
Frequently asked questions
What is the difference between a polar area chart and a pie chart?
In a pie chart, slice angles vary with value. In a polar area chart, all angles are equal and each segment’s radius varies with value.
Which scaling should I use?
Area proportional (the default) is visually accurate. Radius proportional matches some other tools but makes large values look larger than they are.
Can I hide the gridlines?
Yes. Turn off gridlines under Axes & gridlines.
Can values be negative?
No. A segment can’t have a negative length. Negative values are flagged as errors.
How many segments can I use?
Up to 60, though between 4 and 16 is most readable.
Your data stays private
Charts are drawn by your browser. Your data isn’t uploaded to our servers; it is kept only in this browser’s storage, for autosave and saved charts, until you clear it. See our privacy policy.