Quartile Calculator
Calculate Q1, Q2 (median), and Q3 quartiles from a dataset.
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Q2 (Median)
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Q1 (25th Percentile)
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Q3 (75th Percentile)
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IQR (Q3 − Q1)
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Minimum
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Maximum
Recent Calculations
What Is Quartile?
Quartiles divide sorted data into four equal parts. Q1 is the 25th percentile, Q2 is the median, Q3 is the 75th percentile.
Formula
Q1 = median of lower half, Q2 = median, Q3 = median of upper halfExample
For {2, 4, 7, 9, 12}: Q1 = 3, Q2 = 7, Q3 = 10.5, IQR = 7.5.
Frequently Asked Questions
What is the interquartile range (IQR)?
IQR = Q3 − Q1. It measures the spread of the middle 50% of data and is resistant to outliers.
How are quartiles used to detect outliers?
Values below Q1 − 1.5×IQR or above Q3 + 1.5×IQR are considered outliers.