Three treatment groups
R PlantGrowth; Dobson, 1983
Box Plot Maker
FigranEnter your numbers to make a box and whisker plot with its five-number summary.
- Raw data or five-number summary
- Choose your quartile method
- Free SVG and 300 DPI PNG
Groups
Shape
Points
Axis and labels
Brackets
R PlantGrowth; Dobson, 1983
Five-number summary
| Group | n | Min | Q1 | Median | Q3 | Max | IQR | Lower fence | Upper fence | Mean | SD | Outliers |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Control | 10 | 4.17 | 4.53 | 5.155 | 5.33 | 6.11 | 0.8 | 3.33 | 6.53 | 5.032 | 0.583091 | — |
| Treatment 1 | 10 | 3.59 | 4.17 | 4.55 | 4.89 | 6.03 | 0.72 | 3.09 | 5.97 | 4.661 | 0.793676 | 6.03 |
| Treatment 2 | 10 | 4.92 | 5.26 | 5.435 | 5.8 | 6.31 | 0.54 | 4.45 | 6.61 | 5.526 | 0.442573 | — |
Box plot examples
Test scores
Illustrative
Comparing two classes
Illustrative
From a five-number summary
Illustrative
Grouped box plot
R ToothGrowth; Crampton, 1947; Welch t tests run separately in R
Many groups
R chickwts; Snedecor, 1948
Violin plot
R iris; Anderson, 1935
Log scale with outliers
R airquality; New York State Department of Conservation and National Weather Service, 1973
How to make a box plot
Enter values
Add numbers for each group.
See the summary
Review the five-number summary.
Choose a style
Set the shape, points and orientation.
Download
Save your plot as PNG or SVG.
How to read a box plot
The box spans Q1 to Q3, with a line at the median. The whiskers reach the most extreme values inside the fences; points beyond the fences are outliers. The IQR is the width of the box in data units.
Quartile methods
Q1 and Q3 of the 15 scores in the Test scores example, by method.
| Method | Q1 | Q3 |
|---|---|---|
| Median of halves (TI-84, textbooks) | 68 | 85 |
| Tukey hinges (R boxplot) | 69 | 83.5 |
| Linear interpolation (Excel QUARTILE.INC, ggplot2) | 69 | 83.5 |
| Weibull (Excel QUARTILE.EXC, Prism) | 68 | 85 |
Frequently asked questions
How do I make a box plot?
Enter values for each group, choose the quartile method and download your plot.
What is the five-number summary?
It is the minimum, first quartile, median, third quartile and maximum.
What is the interquartile range?
The interquartile range (IQR) is Q3 minus Q1.
How are outliers found?
Values beyond Q1 − 1.5 × IQR or Q3 + 1.5 × IQR are outliers. They remain in your data.
Why do my quartiles differ from Excel or my calculator?
Different programs use different quartile methods. Choose the method that matches your source. Checked against R 4.6.0.
Can I make a box plot from Excel?
Copy your data and paste it into the values field or Paste table.
Box plot or violin plot?
A box plot summarizes quartiles and whiskers; a violin plot also shows the shape of the distribution.
Should I show individual data points?
Showing points can help readers see small samples. Report n and the whisker definition in the figure legend.
Tukey, Exploratory Data Analysis, 1977; Hyndman and Fan, American Statistician, 1996; Langford, Journal of Statistics Education, 2006; Krzywinski and Altman, Nature Methods, 2014; Hintze and Nelson, American Statistician, 1998; Weissgerber et al., PLOS Biology, 2015.
Make your box plot
Enter your data and download the figure.