Excel Speedometer Charts - How to build them and why YOU SHOULDN'T!

Introduction

This tutorial will guide you through the process of building Excel Speedometer Charts, also known as Gauge Charts. While these charts can be visually appealing for displaying data, the tutorial will also highlight their limitations and suggest better alternatives. Understanding both how to create these charts and their drawbacks will enhance your data visualization skills in Excel.

Step 1: Building the Excel Speedometer Chart

Follow these steps to create a basic Speedometer Chart in Excel:

1. Prepare Your Data

   • Create a table with the following columns:
     • A category label (e.g., "Current Value")
     • Target value (e.g., "Target Value")
     • Maximum value (e.g., "Max Value")
   • Example data:

     | Category       | Value |
     |----------------|-------|
     | Current Value  | 70    |
     | Target Value   | 100   |
     | Max Value      | 100   |
     

2. Insert a Doughnut Chart

   • Select your data range.
   • Go to the Insert tab in Excel.
   • Click on "Insert Pie or Doughnut Chart" and select "Doughnut Chart."

3. Add Series for the Chart

   • Right-click on the chart area and select "Select Data."
   • Click "Add" to create a new series for the "Current Value."
   • Set the series name and values to correspond with your data.

4. Format the Chart

   • Right-click on the doughnut chart and choose "Format Data Series."
   • Adjust the angle of the first slice to position the chart correctly.
   • Change the fill color to reflect the current value (e.g., green for the progress).

5. Add a Gauge Needle

   • Insert a new shape (like a line) to represent the needle.
   • Position it at the correct angle based on your current value.

Step 2: Creating Dynamic Chart Labels

To make your chart more informative:

1. Add Data Labels

   • Right-click on the chart and select "Add Data Labels."
   • Format these labels to display the current value dynamically.

2. Use Formulas for Dynamic Labels

   • Create a formula that references the current value cell.
   • Example formula: = "Current Value: " & A2 (assuming A2 contains your current value).

Step 3: Understanding the Problem with Speedometer Charts

While Speedometer Charts may look attractive, they have several drawbacks:

• Misleading Interpretations

  • Users may misinterpret the data since the visual representation can exaggerate small differences.

• Inefficient Use of Space

  • They often occupy more space than necessary, making it harder to compare multiple values.

• Limited Data Context

  • Speedometers provide little context for the data being displayed, which can lead to confusion.

Step 4: Exploring Alternatives to Speedometer Charts

Consider these more effective alternatives for data visualization:

• Bar Charts

  • Great for comparing multiple values side by side.

• Bullet Charts

  • Provide a clear representation of performance against a target.

• Line Charts

  • Useful for showing trends over time, allowing for better data analysis.

Conclusion

Building Speedometer Charts in Excel can be a fun exercise, but it's crucial to recognize their limitations and seek better alternatives for data representation. By following this tutorial, you now have the skills to create a Speedometer Chart while also understanding when to use other chart types for more effective data communication. Explore bullet charts or bar charts for clearer insights in your presentations. Happy charting!