Combo Charts

Advanced charting techniques like combo charts are covered extensively in our Excel classes in NYC. For those located outside New York, find and compare the top in-person Excel classes or online Excel training to master these essential data visualization skills.

Exercise 1

In Exercise 1, we'll construct a combo chart to visualize the relationship between revenue and growth percentage from 2014 to 2017. This exercise demonstrates why understanding your data structure is crucial before selecting visualization methods.

Creating the initial chart follows Excel's standard workflow. Navigate to the Insert tab, locate the Charts group, and identify the combo chart icon. If you're unfamiliar with the icon, hover over each option in the Charts group—Excel's tooltips will identify each chart type for you. Click the combo chart icon and select the first template option.

The resulting chart reveals a common data visualization problem: when you're comparing metrics with vastly different scales, one dataset often gets flattened against the axis. In this case, the percentage growth appears as a nearly flat line at the bottom because the revenue values are orders of magnitude larger. This makes meaningful comparison impossible and defeats the purpose of using a combo chart.

Exercise 2

Exercise 2 addresses this scaling issue through proper chart configuration. Starting with a single cell selected within your data range, insert another combo chart using the same process as before.

This iteration shows marginal improvement—the price per unit line (replacing percentage growth) displays more variation than the previous flat line. However, we can optimize this further through Excel's chart customization tools.

Access the chart modification options by clicking "Change Chart Type." Here's where the magic happens: confirm that "Units Sold" is set as a clustered column and "Price per Unit" is configured as a line chart. The critical step is checking the "Secondary Axis" option for the price per unit data.

This secondary axis transforms the chart's effectiveness entirely. Instead of forcing both datasets to compete against a single scale, each metric now has its own axis with appropriate scaling. Units sold (ranging from $800 at the low end) can now be meaningfully compared with price per unit (topping out at $105) because each operates within its optimal range. The result is a chart where trends, correlations, and divergences become immediately apparent—exactly what professional data visualization should accomplish.

Formatting a Combo Chart

Professional-grade charts require thoughtful formatting to enhance readability and visual appeal. Excel's formatting tools allow you to create publication-ready visualizations that communicate authority and attention to detail.

Begin by selecting any bar in your chart, then navigate to the Format tab to access styling options. In the Shape Styles group, apply "Gradient Fill—Gold, Accent 4, No Outline" to give your bars a polished, professional appearance that stands out without being garish.

Next, click in the chart's background area to modify the overall appearance. Use Shape Fill to select "White, Background 1, Darker 25%"—this subtle background color provides depth without overwhelming your data. You'll find the exact color by hovering over options until the tooltip displays this specific description.

For the chart border, apply Shape Outline in "Gold, Accent 4" to create visual cohesion with your bar colors. Finally, add dimensional depth through Shape Effects by selecting Bevel and choosing "Soft Round." These subtle effects create a sophisticated, three-dimensional appearance that elevates your chart from basic to professional.

Recap

This exercise demonstrates three fundamental principles of effective data visualization in Excel. First, combo charts excel at displaying related metrics with different scales or units of measurement. Second, secondary axes are essential when comparing datasets with significant value disparities—without them, smaller-scale data becomes virtually invisible. Third, professional formatting transforms functional charts into compelling visual communications that command attention and convey expertise.

Mastering these techniques positions you to create sophisticated data visualizations that clearly communicate complex relationships, support strategic decision-making, and enhance your professional credibility in data-driven environments.