Statistics calculator
Interquartile Range Calculator
Calculate quartiles, IQR, Tukey fences, and potential outliers from a numeric dataset.
All values and results stay in this browser tab. This page uses no account, upload, remote calculation, URL state, or persistent storage.
Enter values
Separate values with commas, spaces, or line breaks. Enter 4–5,000 values.
Loading local utility…
Result
Method
Uses the median-of-halves convention. When the count is odd, the overall median is excluded from both halves before Q1 and Q3 are calculated.
Worked example
For 1, 2, 3, 4, 5, 6, 7, 20, Q1 = 2.5, Q3 = 6.5, IQR = 4, and 20 lies above the upper Tukey fence of 12.5.
Limitations
Quartile conventions can produce different Q1 and Q3 values. Tukey fences identify potential outliers; they do not prove that an observation is erroneous.