How to Build an Excel Box Plot Chart

How to make a Box Plot, or box and whisker chart, to show the distribution of the numbers in your data

Introduction

With a Box Plot (box and whisker chart), you can see the distribution of numbers in data. What are the highest and lowest numbers? What was the median number? What was the range of numbers on either side of the median?.

Excel 2013 doesn't have a Box Plot chart type, but you can create your own version, by adding calculations to the worksheet, and using a Stacked Column chart type, with error bars.

To see the steps for creating a simple box plot chart, watch this short video. The written instructions are below the video.

Note: To see the video transcript, go to the Box Plot Chart Video page.

Set Up the Box Plot Data

To create your own box plot chart, the first step is to set up your data. In the screen shot below:

• Column A has month labels, and those will not be used in the chart
• Columns B and C have sales data, with headings in row 3

Enter the Box Plot Chart Formulas

The next step is to enter the formulas that will be used in the chart. Simple formulas calculate the Min, Quartile 1, Median, Quartile 3 and Max values.

Enter the following formulas, then copy them across to column G.

• F4: =MIN(B4:B11)
• F5: =QUARTILE(B4:B11,1)
• F6: =MEDIAN(B4:B11)
• F7: =QUARTILE(B4:B11,3)
• F8: =MAX(B4:B11)

Box Heights

From those calculations, you can calculate the height of each box, and the length of the whiskers. The diagram below shows where each measure appears in the box plot.

To calculate the heights/lengths, subtract the bottom measure from the top one. For example, the upper box height is Quartile 3 minus the Median.. The formulas are listed below the screenshot.

Enter the following formulas, then copy them across to column G.

• F10: =F5
• F11: =F6-F5
• F12: =F7-F6
• F14: =F8-F7
• F15: =F5-F4

Create the Box Plot Chart

To create the Box Plot chart:

1. Select cells E3:G3 -- the heading cells -- then press Ctrl and select E10:G12.
2. On the Excel Ribbon, click the Insert tab, and click Column Chart, then click Stacked Column
3. If necessary, click the Switch Row/Column command on the Ribbon's Design tab, to get the box series stacked.
4. Click on the Base series to select it, and format it with no fill and no border, so it isn't visible in the chart.
5. Remove the Legend

1. Click the top box, and on the Ribbon's Design tab, click Add Chart Element
2. Click Error Bars, and click More Error Bar Options
3. In the Error Bars Options, under Direction, click Plus
4. In the Error Amount Section, click Custom, and click Specify Value
5. Delete the contents of the Positive Error Value box, and select the Whisker Top values on the worksheet

6. Click OK to close the Custom Error Bars window.

1. Click the hidden bottom box, and on the Ribbon's Design tab, click Add Chart Element
2. Click Error Bars, and click More Error Bar Options
3. In the Error Bars Options, under Direction, click Minus
4. In the Error Amount Section, click Custom, and click Specify Value
5. Delete the contents of the Negative Error Value box, and select the Whisker Bottom values on the worksheet

6. Click OK to close the Custom Error Bars window

To finish the formatting, change the fill color for the boxes to light gray, and give them a darker gray border.

Add an Average Marker to Box Plot

After you create a box plot chart, you can add an average marker to each box. To add the average, follow these steps in this video. There are step-by-step instructions below the video

To add an average marker to a Box Plot Chart:

1. Add a blank row in the box plot's data range.
2. Type the label, "Average" in the first column
3. In the remaining columns, enter an AVERAGE formula, to calculate the average for the data ranges.
4. Copy the cells with the Average label, and the formulas
5. Click on the chart, and on the Ribbon's Home tab, click the arrow on the Paste button
6. Click Paste Special.
7. In the Paste Special dialog box, choose "New Series", Values in Rows, and "Series Names in First Column", and click OK

8. If the Average series appears as a Stacked Column, right-click one of the columns, and click Change Series Chart Type

9. Combo chart will be selected in the Chart Type dialog box. In the list of series, find the Average, and change its chart type to Line With Markers, and click OK

10. Click on the line, and on the Ribbon's Format tab, click Format Selection
11. In the Fill & Line section, under Line, select No Line

12. Close the Format Data Series window, and Average marker appears on the chart.

You can download the sample file that was used in this video -- Simple Box Plot Chart. The zipped file is in xlsx format, and does not contain macros.

Quick and Easy Box Plot Builder

If you don't have the time or patience to create your own Excel Box Plot chart, you can invest in a Box Plot Builder. Charting guru, Jon Peltier, offers a time-saving Excel Chart Utility, which includes a Box Plot chart builder, along with 7 other custom chart types.

Video: Box Plot Chart Builder

You can see how well the Box Plot Chart builder works, in this short video.

How the Box Plot Builder Works

Just select your data, click the Box Plot Chart command on the Ribbon, set a few options, and click OK, and your Box Plot chart is ready. A few columns with formulas are added in your workbook, to provide the data for the box plotchart.

The Box Plot also includes an Average marker, and several options for the Quartile calculations, as you can see in the example below.

____

More Tutorials

Box Plot Chart Video

Charts, Line-Column 2 Axes

Charts, Panel

Note: These are affiliate links, and I'll earn a small commission if you purchase the chart utility through these links.

Last updated: October 25, 2018 12:01 PM