Overview
What Is a Quartile Calculator?
This tool divides a sorted data set into four equal parts, calculating Q1 (25th percentile), Q2 (median), and Q3 (75th percentile).
Calculate Q1, Q2, and Q3 of a data set.
This tool divides a sorted data set into four equal parts, calculating Q1 (25th percentile), Q2 (median), and Q3 (75th percentile).
Useful for understanding data distribution and identifying the spread of the middle 50% of values.
Type numbers separated by commas or spaces.
Q1, Q2, and Q3 update automatically.
The first quartile, representing the 25th percentile - 25% of data falls below this value.
The second quartile, which is simply the median of the entire data set.
The third quartile, representing the 75th percentile - 75% of data falls below this value.
Q3 minus Q1, representing the spread of the middle 50% of your data.
No, calculations happen entirely in your browser.
Values below Q1-1.5×IQR or above Q3+1.5×IQR are commonly flagged as potential outliers - see our outlier calculator.
At least 4 for meaningful quartile calculation, though more data gives more reliable quartile estimates.
Yes, box plots visually represent quartiles (Q1, median, Q3) along with the data range.
Yes, completely free with no sign-up required.
Yes, several statistical conventions exist for quartile calculation - this calculator uses a standard common method.