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IQR Calculator

Calculate the interquartile range, quartiles, and full five-number summary for any dataset. Includes step-by-step working, box plot, outlier detection, and complete descriptive statistics.

Q1 · Q2 · Q3 · IQR · Box plot · Outliers · Full descriptive stats · Step-by-step

Dataset Input

Enter numbers separated by commas, spaces, or new lines

Inclusive: The median is included in both halves when splitting the dataset for Q1/Q3.

Quick Examples
Quick Stats
IQR
Min
Q1
Median (Q2)
Q3
Max
n
What is IQR?
IQR = Q3 − Q1 — the spread of the middle 50% of data. Robust to outliers.
Outlier fences:
Lower: Q1 − 1.5 × IQR
Upper: Q3 + 1.5 × IQR
Extreme outliers:
Lower: Q1 − 3 × IQR
Upper: Q3 + 3 × IQR
Quartile Methods
InclusiveMoore-McCabe
ExclusiveTukey / Hinge
MidpointExcel QUARTILE

Different methods may give slightly different Q1/Q3 values, especially for small datasets.

Interpreting IQR
IQR ≈ 0Very concentrated
Small IQRLow spread
Large IQRHigh spread
IQR vs RangeMore robust