Interquartile Range Calculator

This Interquartile Range Calculator finds the first quartile (Q1), median, third quartile (Q3), interquartile range (IQR), outlier fences, whiskers, and potential outliers from a numerical dataset. The IQR measures the spread of the middle 50% of observations and is calculated as Q3 minus Q1, making it a useful robust measure of variability when data contain unusually large or small values. Enter raw values separated by commas, spaces, semicolons, or new lines and the results update instantly. You can choose a common quartile convention, adjust the outlier-fence multiplier, control displayed precision, inspect a live box plot, review the sorted dataset, and copy a concise result summary. Because statistical software can use different sample-quantile definitions, the selected quartile method is always shown so your result can be reproduced accurately in research, coursework, data analysis, and descriptive statistics reporting.