Statistics & Probability
Interquartile Range
Spread of the middle 50% of data.
Formula
Formula
IQR = Q3 − Q1
Variables
| Symbol | Definition | Type & range | Units | Role |
|---|---|---|---|---|
| Q1, Q3 | first & third quartiles | computed result | — | result |
Try it yourself
Interactive calculator
Worked examples
Example 1
Givendata = 1, 2, 3, 4, 5, 6, 7, 8
Result3.5
Example 2
Givendata = 10, 20, 30, 40
Result15