Quartile Calculator
Find the quartiles (Q1, median, Q3) and interquartile range of a list of numbers, by the textbook or spreadsheet method.
Change the values and press Calculate to work out your own figures.
Enter numbers to find the quartiles and interquartile range.
Show the working
- Sort: 1, 2, 3, 4, 5, 6, 7, 8, 9
- Method: median of each half (the middle value left out when the count is odd)
- IQR = 7.5 − 2.5 = 5
How to use it
Enter numbers to find the quartiles and interquartile range.
Paste or type the numbers separated by commas, spaces or new lines. Results are worked out exactly and shown to 12 significant figures; Show the working lists each step.
Key facts
IQR = Q3 − Q1
Why methods differ
There is no single agreed definition of a quartile for small data sets; statisticians list at least nine. They agree for large data sets, and the differences for small ones are usually within one data value.
Questions
What is the interquartile range?
Q3 − Q1: the spread of the middle half of the data.
Why doesn't my answer match Excel?
Excel interpolates; choose the linear interpolation method to match QUARTILE.INC.
Formulas
IQR = Q3 − Q1
Sources
Limitations
- Up to 5,000 values. Values are separated by commas, spaces or new lines, so write 1250 rather than 1,250.