IQR
Interquartile Range Calculator
The spread of the middle half of your data, and the fences that flag outliers.
Result…
How it's calculated
IQR = Q3 − Q1 fences = Q1 − 1.5 × IQR and Q3 + 1.5 × IQR
The IQR ignores the top and bottom quarters, so a few extreme values barely move it. Values beyond the 1.5 × IQR fences are the usual definition of outliers (Tukey). Quartiles and percentiles use linear interpolation between the closest ranks by default (R type 7, Excel PERCENTILE.INC / QUARTILE.INC); the median-of-halves method taught in many courses and used by TI-83/84 calculators can give slightly different values for small data sets, so it is offered as an option for quartiles.
Your numbers, step by step
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