Name: PlotNerd
Author: PlotNerd

1. Overview: Excel Box Plot Capabilities

Excel 2016 and later versions include a native box-and-whisker plot chart type, making it easier than ever to create statistical visualizations. However, understanding how Excel calculates quartiles is crucial, as it uses the QUARTILE.INC function by default, which differs from methods used in R, Python, and other statistical software.

💡 Quick Tip

If you need to match results from R or Python, you'll need to manually calculate quartiles using the appropriate method. Excel's built-in chart uses QUARTILE.INC, which corresponds to R's type 1 quantile method in some cases, but not always. See our quartile compatibility guide for details.

2. Method 1: Built-in Box Plot Chart (Excel 2016+)

Step 1: Prepare Your Data

Organize your data in a single column or row. For multiple groups, arrange each group in separate columns. Here's an example dataset we'll use throughout this tutorial:

Student ID	Test Score
1	85
2	92
3	78
4	96
5	88
6	91
7	79
8	83
9	94
10	87

Try it yourself: Calculate quartiles for this dataset using PlotNerd's calculator to see how Excel's method compares.

85, 92, 78, 96, 88, 91, 79, 83, 94, 87

🧮 Open Quartile Calculator with This Data

Step 2: Insert the Chart

Select your data range (including headers if present)
Go to Insert tab → Charts group → Insert Statistic Chart
Choose Box and Whisker from the dropdown menu
Excel will automatically create a box plot chart

Excel automatically calculates the five-number summary (minimum, Q1, median, Q3, maximum) and displays outliers as individual points beyond the whiskers.

Step 3: Customize the Chart

Right-click on the chart and select Format Chart Area to access customization options:

Show Mean Markers: Add a marker for the mean value
Show Outliers: Toggle outlier point display
Quartile Calculation: Choose between Inclusive (QUARTILE.INC) or Exclusive (QUARTILE.EXC)
Whisker Type: Select how whiskers extend (1.5×IQR is standard)

3. Method 2: Manual Calculation & Chart Creation

For older Excel versions or when you need precise control over quartile calculations, you can manually calculate the five-number summary and create a custom chart.

Step 1: Calculate Five-Number Summary

Create a table with formulas to calculate each statistic:

Statistic	Excel Formula	Result (Example)
Minimum	=MIN(A2:A11)	78
Q1 (First Quartile)	=QUARTILE.INC(A2:A11,1)	82.5
Median (Q2)	=MEDIAN(A2:A11)	87.5
Q3 (Third Quartile)	=QUARTILE.INC(A2:A11,3)	92
Maximum	=MAX(A2:A11)	96

⚠️ Important Note

Excel's QUARTILE.INC function uses a different algorithm than R's default quantile function or Python's numpy.percentile. If you need to match results from other software, you may need to use QUARTILE.EXC or implement a custom formula. See our compatibility guide for detailed comparisons.

Step 2: Create a Stacked Column Chart

Transform your five-number summary into a format suitable for a stacked column chart:

Create helper columns: Lower Whisker (Q1 - 1.5×IQR), Box Bottom (Q1), Box Middle (Median - Q1), Box Top (Q3 - Median), Upper Whisker (Max - Q3)
Select these values and insert a Stacked Column Chart
Format the chart to hide certain series and adjust colors
Add error bars for whiskers

This method gives you complete control but requires more setup. For most users, the built-in box plot chart (Method 1) is recommended.

4. Understanding Excel Quartile Calculations

Excel offers two quartile functions that use different calculation methods:

QUARTILE.INC

Inclusive Method

Includes the minimum and maximum values in the calculation. This is Excel's default method for box plots and uses the formula: Q = (n-1) × p + 1

Use when: You want results that match Excel's built-in box plot chart.

QUARTILE.EXC

Exclusive Method

Excludes the minimum and maximum values. Uses a different interpolation method that may produce different results, especially with small datasets.

Use when: You need results that exclude extreme values or match certain statistical software defaults.

Compare methods: Use PlotNerd's algorithm comparison tool to see how Excel's QUARTILE.INC compares to R, Python, and other methods.

🔄 Compare Quartile Algorithms Side-by-Side

5. Professional Formatting & Customization

A well-formatted box plot communicates your data effectively. Here are key formatting tips:

Color Scheme: Use consistent colors for boxes across multiple groups. Avoid overly bright colors that distract from the data.
Outlier Markers: Make outliers clearly visible but not overwhelming. Consider using a different shape (diamond or star) for extreme outliers.
Axis Labels: Always include clear axis labels with units. For example, "Test Scores (0-100)" is better than just "Scores".
Title: Use descriptive titles that explain what the chart shows, such as "Distribution of Test Scores by Class" rather than "Box Plot".
Gridlines: Light gridlines can help readers estimate values, but avoid heavy gridlines that compete with the data.

Formatting Checklist

✓ Chart title clearly describes the data
✓ Axis labels include units and context
✓ Outliers are clearly marked and explained
✓ Colors are accessible (consider colorblind-friendly palettes)
✓ Legend is present if comparing multiple groups

6. Troubleshooting Common Issues

Issue 1: Box Plot Option Not Available

Symptom: You don't see "Box and Whisker" in the Insert Chart menu.

Solution: Box plots are only available in Excel 2016 and later. If you're using an older version, you'll need to use Method 2 (manual calculation) or upgrade Excel. Alternatively, use PlotNerd's Excel Quartile Calculator which works in any browser.

Issue 2: Quartiles Don't Match Other Software

Symptom: Your Excel quartiles differ from R, Python, or SPSS results.

Solution: This is expected behavior. Excel uses QUARTILE.INC by default, which implements a different algorithm than R's quantile() or Python's numpy.percentile(). See our detailed comparison guide to understand the differences and choose the right method for your needs.

Issue 3: Chart Looks Incorrect

Symptom: The box plot doesn't match your expectations or looks distorted.

Solution: Check your data for:

Missing values (Excel may handle these inconsistently)
Text values mixed with numbers
Incorrect data selection (make sure you selected the right range)
Very small sample sizes (box plots need at least 5-10 data points to be meaningful)

7. Excel vs Other Tools Comparison

While Excel is convenient for quick box plots, other tools offer advantages for statistical analysis:

Feature	Excel	PlotNerd	R/Python
Ease of Use	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐
Algorithm Options	Limited (2 methods)	4+ methods	9+ methods
Cross-Platform	Windows/Mac only	Any browser	Any OS
Data Privacy	Local	100% client-side	Local
Export Options	PNG, PDF	PNG, SVG, CSV	Multiple formats

Try PlotNerd: Compare your Excel results with PlotNerd's multiple algorithm support. See how different quartile methods affect your box plot.

🧮 Open PlotNerd Calculator

❓ Frequently Asked Questions

Q: Why do my Excel quartiles differ from R or Python?

A: Excel uses QUARTILE.INC by default, which implements a different interpolation method than R's default quantile() function (type 7) or Python's numpy.percentile(). These differences are mathematically valid but can produce different results, especially with small datasets. See our quartile compatibility guide for detailed explanations.

Q: Can I create box plots in Excel 2013 or earlier?

A: Excel 2013 and earlier don't have a built-in box plot chart type. You'll need to manually calculate the five-number summary and create a custom chart using stacked columns and error bars, or use an online tool like PlotNerd's Excel Calculator that works in any browser.

Q: How do I show mean on an Excel box plot?

A: In Excel 2016+, right-click the chart, select "Format Chart Area", and check "Show Mean Markers". The mean will appear as an X or diamond marker on the box plot. Note that box plots traditionally show the median, not the mean, so use mean markers judiciously.

Q: Can I compare multiple groups in one Excel box plot?

A: Yes! Arrange each group's data in separate columns, select all columns, and insert a box plot. Excel will create side-by-side box plots for each group. This is useful for comparing distributions across categories, such as test scores by class or sales by region.

Q: What's the difference between QUARTILE.INC and QUARTILE.EXC?

A: QUARTILE.INC (inclusive) includes the minimum and maximum values in calculations and is Excel's default. QUARTILE.EXC (exclusive) excludes these extremes. The choice affects results, especially with small datasets. Use QUARTILE.INC to match Excel's built-in box plot chart, or QUARTILE.EXC if you need to exclude extreme values.

Q: How do I export an Excel box plot for presentations?

A: Right-click the chart and select "Save as Picture" to save as PNG. For higher quality, copy the chart and paste it into PowerPoint or Word, which preserves vector graphics. Alternatively, use PlotNerd to export as SVG for scalable vector graphics perfect for publications.

Related Resources

→ Why Do Excel, R, Python, and SPSS Calculate Different Quartiles?
→ Interactive Guide to Quartile Calculation Discrepancies – Compare all methods (Tukey, R-7, Excel, WolframAlpha) with your data
→ How to Read a Box Plot: A Simple Guide
→ Tukey's Hinges vs. R-7 Quantiles: How to Pick the Right Quartile Method
→ IQR Outlier Detector Tool
→ Excel Quartile Calculator with Multiple Algorithm Support