Measure the spread of the middle half of your data with the interquartile range. Paste your numbers and the tool computes the first quartile, the third quartile, and the IQR, which is simply Q3 minus Q1. Because it ignores the smallest and largest quarter of the values, the IQR is resistant to outliers, unlike the full range or the standard deviation, which makes it a reliable spread measure for skewed data. It is also the basis of the common outlier rule, where anything more than one and a half times the IQR beyond a quartile is flagged as suspect. Box plots draw their box exactly from Q1 to Q3, so the IQR is the box width. The tool also shows the median so you can see where the center sits inside that box. Everything runs locally in your browser.
The IQR is the third quartile minus the first quartile, the spread of the middle half of the data.
It measures spread while ignoring extreme values, so a few outliers do not distort it.
It also shows the first quartile, the third quartile and the median in the same step.
Measure the spread of the middle half of your data with the interquartile range. Paste your numbers and the tool computes the first quartile, the third quartile, and the IQR, which is simply Q3 minus Q1.
Yes. Interquartile Range Calculator is completely free, with no sign-up and no usage limits.
Yes. Interquartile Range Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Interquartile Range Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.