How this calculation works
Find inner and outer fences for a boxplot given its two quartiles.
THE FORMULA
Fences are Q₁−kIQR and Q₃+kIQR, with k=1.5 or 3A worked example
Quartiles of 10 and 18 yield inner fences of −2 and 30.
Good to know
Compute both quartiles using the same convention before entering them.
Reference: OpenStax Introductory Statistics (opens in a new tab) ↗
Read the result
Find inner and outer fences for a boxplot given its two quartiles.
The primary result is labeled “Lower inner fence”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
Compute both quartiles using the same convention before entering them.
For a related exercise, try the statistics calculator.
A few questions, answered
How can I check the default inputs by hand?
Quartiles of 10 and 18 yield inner fences of −2 and 30.
Which rule does this calculator apply?
Fences are Q₁−kIQR and Q₃+kIQR, with k=1.5 or 3