Charts / Glossary
Outlier
A chart word, with the charts that use it.
Definition
An outlier is a value far from the rest, drawn on its own so it is not hidden. It can be an error or the most important point on the chart.
Updated Nov 2, 2026
- 01The whiskersThe usual range of values.
- 02An outlierA dot beyond the whisker, drawn on its own.
Where you see it
043 · Box plotDistribution · AI data
034 · ScatterRelationship · Crypto data
Common mistakes
Deleting outliers to tidy the chart
Check them first: they may be the story.
Letting one outlier set the scale
One huge value squashes the rest. Fit the axis to the bulk and mark the outlier.
Questions
How is an outlier defined in a box plot?
Usually a value more than 1.5 times the box's height beyond the box.
Should outliers be labelled?
Yes, when people will ask what they are.
Related terms
- Whisker
- Quartile
- Median
- Distribution
Every chart word, A to Z.
Open the glossary