What the tool does, how to run it, and what to expect from the result.
The interquartile range is Q3 − Q1, the spread of the middle half of the data. For 3, 7, 8, 9, 12, 12, 15, Q1 is 7 and Q3 is 12, so IQR = 5. Multiply by 1.5 and step outside the quartiles to get Tukey’s outlier fences: 7 − 7.5 = −0.5 and 12 + 7.5 = 19.5. Nothing here falls outside them.
A quick way to understand who this helps, what it solves, and where it connects next.
Students, teachers, analysts and researchers working with data.
Using the interquartile range calculator without installing anything or signing up.
Short answers for the questions people usually have before trying a utility like this.
IQR ignores the top and bottom quarter, so outliers and skew do not inflate it.
=QUARTILE.INC(A:A,3) − QUARTILE.INC(A:A,1). That uses interpolation, so it can differ slightly from textbook quartiles.
Nearby tools from the catalog that fit the same job or workflow.
Find outliers with the 1.5 × IQR rule
Find outliers with the 1.5 × IQR rule. Free, instant, in your browser.
Most frequent value, with a frequency table
Most frequent value, with a frequency table. Free, instant, in your browser.
Any percentile of a list, and percentile rank
Any percentile of a list, and percentile rank. Free, instant, in your browser.
Range, minimum, maximum and IQR
Range, minimum, maximum and IQR. Free, instant, in your browser.
Geometric, arithmetic and harmonic means
Geometric, arithmetic and harmonic means. Free, instant, in your browser.
Mean, median, mode and range in one go
Mean, median, mode and range in one go. Free, instant, in your browser.
Cleanor puts these tools in one app: compress and convert images, video, and audio, work with PDFs, and scan text right on your device. Plus free up storage and clear inbox clutter with Email Cleaner. Start with a free trial.
Results update as you type. Everything runs in your browser.
Quartiles use the median-of-halves method taught in most textbooks and used by TI-83/84 calculators. Excel’s interpolated values are shown for comparison.