Free tool · Visual Communication
Which Chart Should I Use? A Chart Chooser for Legal and Business Data
Choose a chart by starting from what the reader needs to see, not from the chart you know how to make. To compare values across categories, use a sorted horizontal bar chart that starts at zero. To show change over time, use a line chart. To show the parts of a whole, prefer sorted bars to a pie, and use a stacked bar for parts over time. To show how results are spread, use a histogram. To show whether two things move together, use a scatter plot. For a ranking, use sorted bars with values. For a process, use a flow diagram; for a sequence of dated events, a timeline. Use a map only if location is the point. If the reader needs exact values for a few items, a well-made table beats any chart. Whatever the form, give the chart one message, state it in the title, sort and label directly, use one strong colour and grey, and remove clutter such as 3D effects, gridlines and decoration.
Tool · Chart Chooser
For your purpose, use: A horizontal bar chart, sorted by value.
A horizontal bar chart, sorted by value
Bars compare lengths from a common baseline, which people judge accurately, and horizontal bars leave room for readable labels.
- Sort from largest to smallest unless the categories have a natural order.
- Start the axis at zero.
- Label the bars directly and drop gridlines you do not need.
- Colour the bar that carries your point and grey the rest.
Alternatives: Dot plot (when values are far from zero and the differences matter); Table with data bars.
Avoid
- 3D effects and decorative shading: they distort and add nothing.
- A rainbow of colours with no meaning: use one colour, and a second only to point at the main message.
- For a general audience, state the message in the title (‘Complaints doubled in two years’), use direct labels and cut everything that does not serve the message.
Start from what you want the reader to see, not from the chart you know how to make. Choose the purpose of the picture, the number of categories or time points and who will look at it, and the tool suggests a chart type with the reasons, how to draw it, alternatives and the mistakes to avoid. The advice follows common rules of good practice; the best chart for a real audience also depends on what they already know. Runs in your browser; nothing is stored or sent.
How to use it
- Choose what the reader should see: a comparison, a change, parts of a whole, a spread, a relationship, a ranking, a process or a place.
- Enter the number of categories and time points and the audience.
- Read the recommended form, the reasons and how to draw it.
- Read the alternatives, the things to avoid and the warnings for your audience.
Common questions
Why are pie charts discouraged?
People judge angles and areas poorly, and it gets worse with more slices. A sorted bar chart with value labels usually answers the same question more accurately.
When is a table better than a chart?
When readers need exact values for a handful of items, the units differ, or they will look things up rather than see a pattern.
Does the tool draw the chart?
No. It recommends a form and tells you how to draw it. You make the chart in a spreadsheet or presentation program.
Learn the law behind the tool
This tool is part of our Visual Communication course, with lectures, concept maps, flashcards, interactive exercises and a capstone case. Visual Storytelling for Lawyers: Choosing the Right Chart.
More free law tools
General information, simplified, mainly on American law, not legal advice. States and countries differ, and real cases turn on facts that a tool cannot capture.