Interquartile Range Calculator
Calculate the interquartile range (IQR) of a dataset. Enter numbers separated by commas to compute Q1, Q3, median, and IQR.
Published by:
isCalculator Editorial Team
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How to use this tool?
This calculator computes the Interquartile Range (IQR) for a dataset. The IQR measures the spread of the middle 50% of your data.
- Enter your data in the input field as a comma-separated list of numbers (e.g.,
1,2,3,4,5,6,7,8,9). - Click "Calculate IQR" to process the data.
- Review the results:
- Sorted Data – your numbers arranged in ascending order.
- Count (n) – total number of values.
- Q1 (25th percentile) – median of the lower half.
- Median (Q2) – middle value of the dataset.
- Q3 (75th percentile) – median of the upper half.
- IQR = Q3 – Q1, displayed as the final result.
- Step-by-step explanation is shown below the results, detailing how each quartile and the IQR were calculated.
Note: The calculator requires at least two numbers. All values must be numeric; non-numeric entries will trigger an error message.
Previous Results
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Frequently Asked Questions
The interquartile range (IQR) is a measure of statistical dispersion, equal to the difference between the third quartile (Q3) and the first quartile (Q1). It represents the middle 50% of the data.
First, sort the data. Then find the median (Q2). The median of the lower half is Q1, and the median of the upper half is Q3. IQR = Q3 - Q1.
The IQR indicates the spread of the middle half of the data. A larger IQR suggests greater variability, while a smaller IQR indicates that the data points are closer together.
