In statistical dispersion, Interquartile range (IQR) is the measurement of difference between third and the first quartiles. IQR is otherwise called as midspread or middle fifty. InterQuartile range is expressed as QR = Q3 - Q1. It is the most important basic robust measure of scale and variability. Use this online interquartile range calculator to find the values of first quartile, third quartile, median and inter quartile range. This IQR calculator tool is good for computing the results in the quicker time.