📦Quartile & IQR Calculator
Find Q1, median, Q3, IQR, and outliers from any data set.
Free IQR Calculator
Need the quartiles, interquartile range, and outliers for a data set? Our free IQR calculator finds Q1, the median, Q3, and the IQR instantly, and flags any outliers using the standard 1.5×IQR rule.
Paste in your data, and see the full working — the sorted list, how it's split into halves, and how each quartile is derived from those halves — plus a box-and-whisker diagram that visualizes the five-number summary and highlights any outlying points. This calculator uses the exclusive (Tukey) median-of-halves method — since different tools can define quartiles slightly differently, the method is stated clearly.
Great for exam prep, lab reports, and spotting outliers in a small data set. No sign-up, no downloads, completely free.