# IQR - Interquartile Range

Returns the interquartile range (IQR), also called the midspread or middle fifty.

## Syntax

IQR(X)

X is the input data series (one/two dimensional array of cells (e.g. rows or columns)).

## Remarks

1. The input time series data may include missing values (e.g. #N/A, #VALUE!, #NUM!, empty cell), but they will not be included in the calculations.
2. The Interquartile range is defined as follows:
$$\mathrm{IQR}=Q_3-Q_1$$
Where:
• $Q_3$ is the third quartile
• $Q_1$ is the first quartile
3. Interquartile range (IQR) is a robust statistic because it has a break down point of 25%. It is often preferred to the total range.

## Examples

Example 1:

 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
A B
Date Data
1/1/2008 #N/A
1/2/2008 -1.28
1/3/2008 0.24
1/4/2008 1.28
1/5/2008 1.20
1/6/2008 1.73
1/7/2008 -2.18
1/8/2008 -0.23
1/9/2008 1.10
1/10/2008 -1.09
1/11/2008 -0.69
1/12/2008 -1.69
1/13/2008 -1.85
1/14/2008 -0.98
1/15/2008 -0.77
1/16/2008 -0.30
1/17/2008 -1.28
1/18/2008 0.24
1/19/2008 1.28
1/20/2008 1.20
1/21/2008 1.73
1/22/2008 -2.18
1/23/2008 -0.23
1/24/2008 1.10
1/25/2008 -1.09
1/26/2008 -0.69
1/27/2008 -1.69
1/28/2008 -1.85
1/29/2008 -0.98

Formula Description (Result)
=IQR($B$2:$B$30) Interquartile Range (2.380)