How to Read a Box Plot Chart? Easy-to-follow Steps

A Box Plot is one of the best-suited charts to use if your goal is to display high-level attributes of your data, such as quartile, mean, median, skewness, and standard deviation.

More so, the chart is incredibly easy to read (as you shall witness later).

So how can you access the chart?

Google Sheets seem to be the obvious choice because it’s free to access. However, the cloud-hosted spreadsheet application does not natively support Box Plots.

Think beyond Google Sheets if you intend to display data attributes, such as mean, outliers, and quartiles in your data. We’re not advocating you do away with Google Sheets. 

The tested and proven option is downloading and installing a particular add-on (which we’ll talk about later) into your Google Sheets to access ready-to-go Box Plot Charts.

Table of Content:

1. What is the Box Plot Chart?
2. How to Read a Box Plot? Easy-to-follow Steps
3. When should you Use a Box Plot?
4. How Do You Calculate a Box Plot?
5. What are the Advantages of Using Box Plot in your Data Stories?
6. Box Plot Best Practices
7. How to Generate Visually Stunning and Ready-to-go Box Plot Charts?
8. Wrap Up

What is the Box Plot Chart?

A Box Plot is a visualization design that uses box plots to display insights into data.

The chart simplifies bulky and complex data sets into quartiles and averages. Also, you can use the chart to pinpoint outliers in your data. The Box Plot segments key variables in quarters or (quartiles).

The chart displays your data’s shape, variability, and center (or median) information. Also, you can leverage the chart to determine the skewness of data points.

Essentially, a Box and Whisker Chart shows the following points of data:

• Minimum range
• Lower quartile
• Median
• Upper quartile
• Maximum range

Keep reading because we’ll cover how to read a Box Plot chart in the coming section.

How to Read a Box Plot? Easy-to-follow Steps

The Box Plot Chart is an exploratory graphic, which John W. Tukey first created to display the distribution of a dataset.

To interpret the chart, you’ve got to know its elements and their meaning. Check the elements below:

Three out of the five summary numbers are displayed by default (median, minimum number, and maximum number). You have an option to display the other two summary numbers (upper and lower quartiles).

Besides the five summary numbers, the visualization displays the following:

• Minimum score
• Median
• Maximum Score
• Lower Quartile
• Upper Quartile

Let’s check out the elements in detail.

• The minimum score is the lowest score, excluding outliers (shown at the end of the left whisker).
• Lower Quartile: 25% of all variables fall below the lower quartile value.
• The median is the mid-point of the data and is shown by the line that divides the box into two parts (sometimes known as the second quartile). Half the scores are greater than or equal to this value, and half are less.
• The upper quartile is 75% of all variables that fall below the upper quartile value (also known as the third quartile). Thus, 25% of data points are above the value.
• The maximum score is the highest score, excluding outliers (shown at the end of the right whisker).
• Whiskers: The upper and lower whiskers represent scores outside the middle 50% (i.e., the lower 25% of scores and the upper 25% of scores).
• The interquartile range (IQR) ranges between the 25th and 75th percentile).

Keep reading because we’ll address the following question in the coming sections: how do you calculate a Box Plot?

When should you Use a Box Plot?

Use the Box and Whisker Chart in the following scenarios:

• Your data should have continuous or categorical attributes to get the most from the visualization design.
• Use the visualization design to conduct A/B tests in marketing.

How to read a Box Plot should never consume your valuable time. Keep reading to discover more.

How Do You Calculate a Box Plot?

Box and Whisker Plot show the distribution of key data points along a number line.

You can generate the chart by ordering a data set to find the median, upper and lower quartiles, and upper and lower extremes. To calculate values, such as mean, follow the steps below:

• Order the data from least to greatest.
• Find the median or middle value that splits the data set into two equal groups. If there is no one middle value, use the average of the two middle values as the median.
• Find the median for the lower half of the data set.
• Find the median for the upper half of the data set.
• Use these five values to construct a Box Plot displaying the following: lower extreme, lower quartile, median, upper quartile, upper extreme.
• Draw vertical lines through the lower quartile, median, and upper quartile.
• Form a box by connecting the vertical lines from the lower quartile, median, and upper quartile.
• Plot the whiskers from the extremes of the box.

Now that we’ve just addressed the following question: how do you calculate a Box Plot? Let’s head to the advantages and benefits you can expect from the chart.

What are the Advantages of Using Box Plot in your Data Stories?

Check out the advantages of the chart below:

• A Box and Whisker Graph can help you to visualize large datasets.
• You can easily detect the symmetry of the data at a glance by using the chart.
• Unlike other data visualization techniques, the Box Plot displays outliers.

As we said, how to read a Box Plot should never be overwhelming. Keep reading to discover more.

Box Plot Best Practices

To get reliable insights, use the visualization design for the following:

• Compare Multiple Groups

Box Plots are best-suited for comparing distributions between key groups in data. The charts are compact in design to help you display a ton of information without clutter.

• Consider the Order of Key Groups

If the groups displayed in a Box Plot lack an inherent order, arrange them to highlight patterns and trends using the median.

How to Generate Visually Stunning and Ready-to-go Box Plot Charts?

Google Sheets is one of the most-used visualization tools among businesses and professionals worldwide.

However, this cloud-hosted spreadsheet tool comes with very basic Box and Whisker Charts, which require a lot of extra work in editing.

We’re not recommending you do away with the spreadsheet app.

You can turn Google Sheets into a reliable Box and Whisker Plot generator loaded with ready-made and visually stunning charts by installing third-party add-ons, such as ChartExpo.

Why ChartExpo?

ChartExpo is an add-on for Google Sheets you can easily install to create beautiful visualizations.

With a large number of advanced visualizations, ChartExpo turns your complex, raw data into compelling, easy-to-digest, visual renderings that tell the story of your data.

The Box and Whisker Plot generator produces simple and clear visualization designs with just a few clicks. Yes, ChartExpo generates Box and Whisker Charts that are amazingly easy to interpret, even for non-technical audiences.

Example

This section will use the Box and Whisker Plot example to display insights into the table below.

You don’t want to miss this.

Category	2019	2020	2021
Appetizer	873	262	548
Mains	632	981	790
Desserts	672	939	198
Drinks	716	901	185
Appetizer	354	598	119
Mains	419	639	597
Desserts	593	619	928
Drinks	560	282	399
Appetizer	898	1034	729
Mains	179	336	735
Desserts	805	150	109
Drinks	683	501	793
Appetizer	1366	425	525
Mains	1291	809	539
Desserts	1129	425	774
Drinks	201	411	228

Install the ChartExpo add-on for Google Sheets using this link and then follow the simple and easy steps below.

• Open your Google Sheets application and paste the table above.
• Open the worksheet and click the Extensions
• Then click Charts, Graphs & Visualizations by ChartExpo button.
• Finally, click the Open button in the dropdown.

• Click the Add New Chart button to initiate ChartExpo’s engine.

• Click the Search Box and type “Box and Whisker Column Chart,” as shown below.

• Select the sheet holding your data and select the Metrics option. Fill in the numerical numbers (in our case, we’ll use 2019, 2020, and 2021).
• Select the Dimensions button and fill in the dimensional data (we’ll use category), as shown below.

• Finish the simple process by clicking the Create Chart button on the Box and Whisker Plot generator (ChartExpo).

How to Edit the Box and Whisker Plot in ChartExpo?

To add additional details, such as title in your chart, follow the steps below:

• Click the Edit button and then click the pencil-like marker near the title section, as shown below.

• Once the Chart Header Top Properties window pops up, click the Line 1 button and fill in the title.

As we said, how to read a Box Plot should never stress you. Use ChartExpo to access ready-made charts for your data stories.

• Save your new changes by clicking the Apply.

• Check out the final chart, as shown above.

FAQs:

Why should you use a Box and Whisker Plot?

A Box and Whisker Chart shows the data distribution into quartiles highlighting the mean and outliers. The boxes may have lines extending vertically called “whiskers.” These lines indicate variability outside the upper and lower quartiles.

Other points outside those lines or whiskers are considered outliers.

When should you use a Box and Whisker Plot?

Use a Box and Whisker Chart if you’ve got two or more key variables in your data. Besides, the chart is amazingly easy to read and interpret, making it ideal for data storytelling.

Also, use the visualization design if your goal is to display comparison insights into your data.

What are the other names of a Box plot?

A Box Plot is a visualization design that uses box plots to display insights into data. The chart simplifies bulky and complex data sets into quartiles and averages.

The chart goes by multiple names, namely:

• Box Plot
• Box and Whisker Diagram
• Box and Whisker Chart
• Box Plot Chart

Wrap Up

As we said, a Box Plot is one of the best-suited charts to use if your goal is to display high-level attributes of your data, such as quartile, mean, median, skewness, and standard deviation.

More so, the chart is incredibly easy to read (as you shall see later).

So how can you generate the visualization design?

Google Sheets seem to be the obvious choice because it’s free to access. However, the cloud-hosted spreadsheet application does not natively support Box Plots.

Think beyond the spreadsheet application if you intend to display attributes, such as mean, outliers, and quartiles in your data.

What’s the solution?

We recommend installing third-party apps, such as ChartExpo, into your Google Sheets to access ready-made Box Plots.

ChartExpo is an add-on you can easily download and install in your Google Sheets app. Besides, this tool comes loaded with insightful and easy-to-interpret Box Plots. You don’t need programming or coding skills to visualize your data using ChartExpo.

How to read Box Plot should never be a stumbling block to you. Use ChartExpo to generate visually stunning, insightful, clear, and ready-to-go visualization designs.

Sign up for a 7-day free trial today to access easy-to-interpret and ready-made Box Plots for your data stories.