Box Plot Chart
Data
Display Settings
Free Online Box Plot Chart Maker
What is a Box Plot Chart?
A box plot (also called a box-and-whisker plot) summarizes a dataset using five statistics: minimum, first quartile (Q1), median, third quartile (Q3), and maximum. It reveals how data is distributed — its spread, skew, and central tendency — in a single compact visual. Use it when you need to compare distributions across groups or surface outliers that a simple average would hide.
Key Features
Auto-calculate from raw values
Paste in raw numbers and the chart computes quartiles, median, and whiskers automatically — no manual statistics needed.
Tukey or min/max whiskers
Choose Tukey whiskers (1.5 × IQR) for standard outlier detection, or min/max whiskers to show the full data range.
Outlier visualization
Outlier points are plotted individually beyond the whiskers, so extreme values are visible without distorting the box.
Mean marker overlay
Optionally display the mean alongside the median to highlight skewness and asymmetry in your distribution.
Multi-group comparison
Add multiple categories side by side to compare distributions across departments, cohorts, or time periods at a glance.
Horizontal or vertical layout
Switch orientation to fit your slide or report — vertical for time-series groups, horizontal for long category labels.
Best For
When to Use
- When you need to show data spread, not just an average or total
- When comparing distributions across two or more groups side by side
- When outliers are meaningful and shouldn't be hidden in an aggregate
- When your dataset has at least 5-10 values per group to make quartiles meaningful
- When you need to reveal skewness or asymmetry in your data
- When side-by-side histograms would be too cluttered for your audience
Common Mistakes
- !Using a box plot with fewer than 5 data points per group — quartiles become misleading at small sizes
- !Forgetting to label axes with units, leaving readers unsure what the values represent
- !Choosing min/max whiskers when a few extreme values stretch them to the point of hiding the box
- !Comparing groups with very different sample sizes without disclosing the difference to readers
- !Using a bar chart when you want to show distribution, not just the mean
- !Treating outliers as errors to remove rather than investigating what caused them