IQR calculator

Calculate the interquartile range — the spread of the middle 50% of your data. IQR = Q3 − Q1.

Data

IQR formula

IQR = Q3 − Q1

The IQR represents the range of the middle 50% of values. It's resistant to outliers, unlike the full range.

Outlier detection

Outliers are values below Q1 − 1.5×IQR or above Q3 + 1.5×IQR. This is the "1.5 IQR rule" used in box plots.

Examples
1 to 13 by 2 Even numbers 2-12 Tens 10-90
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Quartiles Outlier detection Five number summary Statistics