If you’re new to building charts, it can be hard to know where to start. Chances are, you’ve messed around in Excel at one point or another, but there’s more to building an effective chart than knowing which buttons to press. Before you build your next chart (or your first), here are some design principles to guide you.

1. It’s Clear and Simple

Let clarity be your guide. All the data points and fancy diagrams in the world mean nothing if no one can understand what they’re seeing. It’s important to consider your audience, but even the most technical folks don’t want to decipher a complicated chart. A simple chart can still show complicated data. 

In fact, simplicity is even more important with complicated data. Instead of building a big chart full of tiny details, focus on the details that matter. Know what question you want to answer, and define the parameters of your chart accordingly. Charts that provide a “general overview” of things can be misleading, and they aren’t always useful. How many times have you seen a chart and thought, “that’s interesting, but what am I supposed to do about it”? Don’t just throw information at people. Give them information they can act on.

Most people don’t have time to sit around looking at a chart, so be sure the visualizations they do see deliver real value. Now, not every chart is going to lead to immediate action, some are more for context, or to make people aware of things outside of their purview, but every chart should have something useful to say.

Remember that Data is the star of the show, not the methodology, not the design, and not even the visualization itself. If the data is not clear in your chart, you’re doing it wrong. Remember that the goal of any chart is to communicate information, even if that comes at the price of a pretty chart. It’s better to make it clear than to make it pretty.

2. It’s Clean and Lean

We’ve all seen charts with fancy graphics, 3D effects, and funky font choices. Charts like these show you know where the advanced settings tab is, but they’re bad at showing information. Skip the window dressing and get straight to the point. Dieter Rams, the legendary industrial designer from Braun once said, “the best design is as little design as possible.” Think about the elements of your chart that don’t need to be there. For example, you might not need a legend, or a background. You can also get rid of borders and special effects like drop shadows. When you take away what’s unnecessary, you’re left with what matters. Effects might make a chart pretty, but restraint will make it elegant.

Consider the following chart. It’s full of information, but it’s incredibly hard to read. There’s too much to look at, and it’s hard to distinguish one data point from another. Units aren’t clear, and there’s no prevailing message.

Blog Vendor Sales

Charts that say too much often end up saying nothing. If you have to squint your eyes, it’s probably too complicated. With more focus, your chart might say less, but it says it with confidence. In the chart below, it’s easy to see what’s happening.

Blog Sales by Quarter

Think about the dashboard on your car. It gives you all the information you need to drive. At the same time, it doesn’t let the data distract you from what matters. For example, you don’t need to know exactly how many gallons of gas you have. This information might be a little helpful, but you rarely need more than a general idea.

3. It’s Honest

They say there are three kinds of lies: lies, damn lies, and statistics. When designing a chart, it’s tempting to bend the data to suit your needs, but it will only hurt you (and the organization) in the long run. Furthermore, not every lie is obvious. Changing the data is obviously dishonest, but it’s equally dishonest to omit something important, downplay bad news, or fiddle with parameters until you get the “results” you want. If there’s a piece of data so scary you want to hide it, there’s a good chance it has something important to say.

4. It Tells a Story

It’s easy to look at a chart as something that stands alone, but they’re always part of a bigger picture. A chart about sales figures might make it seem like your salespeople are doing a great job, but an additional chart might show that it’s mostly one person behind the surge.

While it’s important to keep your charts simple and honest, it’s okay to use multiple charts to create a narrative. If your data is telling a story, make sure people hear it.

5. It Uses the Right Chart Type

There are several kinds of chart, and choosing the right one is crucial to getting your message across. Between bar charts, pie charts, and line graphs, there’s usually a chart that’s perfect for your needs. For example, if you have more than 8 or so categories, a pie chart might be a bad choice, but a bar chart might be perfect. For a better understanding of what chart to use, stay tuned to this blog. We’re working on a guide to different chart designs.

To learn more about designing charts, check out our Resources page.