IQR (Interquartile Range) Calculator

Q1 (P25) • Q3 (P75) • Linear or nearest rank • value:count supported

Inputs

Numbers

Separators: comma, space, newline, semicolon. Frequency format: value:count, where count must be a positive integer.

Quartile method

Q1 is the 25th percentile and Q3 is the 75th percentile using the selected method.Different quartile conventions can produce slightly different Q1, Q3, and IQR values for the same dataset.

Options Show sorted preview

Large datasets are previewed in compressed form.

Action

Updating…

Use this IQR Calculator to find the first quartile (Q1), median, third quartile (Q3), and interquartile range of a numeric dataset.

Calculation Method

Q1 = 25th percentile

Median = 50th percentile

Q3 = 75th percentile

IQR = Q3 − Q1

The calculator supports both linear interpolation and nearest-rank quartile methods.

Example

For:

1, 2, 3, 4, 5, 6, 7, 8

Using the calculator’s linear interpolation method:

Q1 = 2.75

Q3 = 6.25

IQR = 6.25 − 2.75 = 3.5

Important Note

Quartile formulas vary between calculators and statistical software, so Q1, Q3, and IQR may differ slightly depending on the selected method. Use the same convention when comparing datasets.

Source

OpenStax Introductory Statistics 2e — Quartiles and Percentiles

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