Radar and spider chart paper
Guide · Updated 2026-09-04 · 3 min read
A radar chart — also called a spider or star chart — is the quickest way to show several measures about one thing in a single picture. Skills, product features, survey scores and fitness profiles all fit it. This guide explains how the grid works, how to plot on it, the traps to avoid, and when it beats a bar chart.
What a radar chart shows
A radar chart plots several variables on axes that all share one center, like spokes on a wheel. Each axis is a category — strength, speed, price, sound quality — and the distance out along it is the score. Join the plotted points and you get a shape; the shape is the whole point, because its overall size and where it bulges or pinches tell a story at a glance. Two shapes overlaid make a comparison instant.
The anatomy of the grid
- Axes radiate from the center, one per category, evenly spaced around the circle. Six categories sit 60° apart, eight sit 45° apart, and so on.
- Rings mark the scale, stepping out from the center. If your scores run 0 to 10, five rings make each ring worth two points.
The radar chart generator lets you set how many axes you need and how many rings mark the scale, so the blank matches whatever you are scoring.
How to plot on it
Decide a common scale for every axis — say 0 at the center to 10 at the rim. For each category, count out along its axis to the score and mark a point. When every axis has a point, join them in order around the chart and, if you like, lightly shade inside. To compare two subjects, plot both on the same chart in different colors; the overlap and the gaps are the comparison.
The traps to avoid
Radar charts are persuasive, which makes their pitfalls worth knowing:
- Area exaggerates. Because the plotted shape’s area grows with the square of the values, a chart can look far more different than the numbers really are. Read the points, not just the blob.
- Axis order changes the picture. The same scores in a different order round the circle make a different shape. Keep a consistent, sensible order.
- Too many axes turn to mush. Past eight or ten categories the chart is hard to read; a table or bar chart may serve better.
- Mismatched scales mislead. If axes measure different things, normalise them to a common 0–10 (or 0–100%) first.
Radar versus bar chart
A bar chart is better for reading exact values and ranking them. A radar chart is better for showing a profile — the overall balance of strengths and weaknesses of one subject, and how two subjects differ in shape. Use radar when the pattern matters more than the precise numbers: skills reviews, product or option comparisons, survey results, and sports or fitness profiles. Print it true to size (see the printing guide) so the rings stay evenly spaced. For a continuous curve around a center rather than a handful of category scores, use polar paper instead.