Radar Chart Maker

How to Use the Radar Chart Maker

1. 1. Enter one axis per line. A label, a comma, then the value — Argument, 3. A table pasted from a spreadsheet works as it is; with decimal commas, separate cells with semicolons: Argument; 3,5. You need at least three axes.
2. 2. Add series. More values on a line — Argument, 3, 4 — draw more shapes, one color and marker shape per series. A first line such as Criterion, Draft 1, Draft 2 names them in the legend. Up to eight series are drawn.
3. 3. Choose the scale. Use One scale for every axis when all the axes share a unit; pin the minimum and maximum if you want, say, a fixed 0–5 rubric scale. Use Each axis as a share of its own maximum only when the axes have different units.
4. 4. Label it and export. Write a title, pick a color and decide whether each point shows its value. Turn on APA style figure for a paper, then download the SVG (sharp at any size) or a PNG 1,280 pixels wide.

What a Radar Chart Shows

A radar chart, also called a spider or web chart, puts several variables on spokes that meet at a center. Each value is a point on its spoke — the farther from the center, the larger the value — and the points of one series are joined into a shape. It answers one question well: what is this profile like? Which criteria are strong, which are weak, and how does one profile compare with another on the same set of criteria.

It is a good fit for a rubric scored on several criteria, a student's results across skill areas, a product or method rated on the same attributes, or a before-and-after profile. It is a poor fit for exact values, for more than a few series, or for data with a natural order along one dimension — time, dose, age — where a line graph shows the trend directly.

Honest Limits of Radar Charts

Radar charts are easy to make and easy to misread. Four things to know before you put one in a paper.

• Area exaggerates. The eye reads the size of the filled shape, but the area grows with the square of the values: if every value doubles, the area quadruples. A shape that looks four times as big describes values only twice as large. That is why the Fill the shapes option is on by default but easy to switch off — an outline alone invites comparing points, which is the honest reading.
• Axis order changes the shape — and the area. The same values in a different order give a different polygon. With four axes and the values 5, 5, 1, 1 taken as radii, the polygon covers 18 square units; reorder the same values to 5, 1, 5, 1 and it covers 10. No order is correct, so put related criteria next to each other and say that the order is a choice.
• Shared scale or not. On a shared scale, a point twice as far out is twice the value, and the center is the scale's minimum (zero unless you pin it). With each axis scaled to its own maximum, the center is zero but the rim means a different amount on every spoke, so the chart shows each axis's share of its own maximum — not which axis is larger. The chart labels each axis with the value its rim stands for.
• Crowding. Past about eight to ten axes the names collide and the spokes lie too close to compare; past three series the shapes overlap into a tangle. Split the data into several small charts, or use a bar graph, which puts every value on a common baseline.

Missing values are not read as zero: a series with a blank cell has a gap in its outline, and an open outline is never filled. Negative values are drawn at the center on a per-axis scale; on a shared scale they sit below zero, with the center at the scale's minimum.

Formatting a Radar Chart as an APA 7 Figure

APA style keeps the figure's number and title in your paper's text, not inside the image. APA style figure takes the title out of the image, sets the figure number in bold and the title in italic title case above the chart, and keeps the legend inside the figure. Copy number and title puts both on the clipboard, formatted, to paste above the image. The rules come from APA's figure setup guidelines.

• Name the scale in the Note. below the figure — Scores range from 0 to 5; the outer ring is 5 — since a radar chart has no axis title to carry it.
• Distinguish series by marker shape as well as color: these charts give each series its own marker, so the figure still reads in grayscale. The colors are the colorblind-safe Okabe–Ito palette; you can check any figure with the Color Blindness Simulator.
• If you reproduce a figure from a published source, you need permission and a credit line; see How to Cite a Figure or Table Reproduced from Another Source.

Frequently Asked Questions

What is a radar chart used for?

A radar chart compares profiles: one or a few series measured on the same handful of criteria. Typical uses are a rubric scored on several dimensions, a student's skills, a product or method rated on the same attributes, and a before-and-after comparison. It shows which criteria stand out and how profiles differ in shape — not exact values, for which a table or bar graph is better.

Are radar charts bad?

They are not bad, but they are easy to misuse. The filled area grows with the square of the values, the shape depends on the order of the axes, and many axes or series make them unreadable. Used for a few series on a handful of axes that share one scale — and read by comparing points rather than areas — they are a compact way to show a profile.

How many axes should a radar chart have?

Between five and eight is a common rule of thumb, and at least three are needed for a shape at all. Fewer than five and a bar graph is clearer; beyond about ten, the names crowd and neighboring spokes are too close to compare. This tool draws up to 30 axes but warns above 12.

Does the order of the axes matter on a radar chart?

Yes. The shape, and the area inside it, change when you reorder the axes, because each point is joined to its two neighbors. There is no correct order. Put related criteria next to each other, keep the same order across charts you want to compare, and avoid reading meaning into the area. This tool draws the axes in the order of your lines, clockwise from the top.

Can a radar chart have axes with different units?

Only if each axis is scaled separately. Choose Each axis as a share of its own maximum: every spoke then runs from zero to the largest value on that axis, and its name shows what the rim stands for, such as Speed (100% = 120). The chart then compares each series with the best result on every axis — it cannot say that one axis is larger than another, because they no longer share a scale.

How do I make a radar chart from spreadsheet data?

Copy the table with the criteria down the first column and one column per series, with a header row naming the series, and paste it into the box. Tabs from a spreadsheet are recognized automatically. If your series run across rows instead, transpose the table first in the spreadsheet — paste-special with Transpose in Excel and Google Sheets.