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Interquartile Range from Q1 and Q3 Calculator

IQR = Q3 − Q1, the spread of the middle 50%.

Calculates IQR = Q3 − Q1. Also computes the lower and upper fences for outlier detection: lower = Q1 − 1.5×IQR, upper = Q3 + 1.5×IQR.

Priya Venkatesan By Priya Venkatesan
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

IQR = Q3 − Q1; fences = Q ± 1.5·IQR

In depth

Calculates IQR = Q3 − Q1. Also computes the lower and upper fences for outlier detection: lower = Q1 − 1.5×IQR, upper = Q3 + 1.5×IQR.