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Quartile & IQR Calculator

Calculate Q1, median, Q3 and the interquartile range from raw data.

Reviewed/updated September 8, 2026
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What is the Quartile & IQR Calculator?

Calculate Q1, median, Q3 and the interquartile range from raw data. ITS Research Solution keeps the interactive tool above the explanation so you can calculate first and then review the method used.

Formula or method

IQR = Q3 − Q1; quartiles are estimated by linear interpolation on sorted observations.

How to use this tool

Enter the requested values using consistent units, run the calculation and review the main result plus any supporting values. For a sorted dataset, the tool identifies the 25th, 50th and 75th percentiles.

Interpretation and limitations

Different statistical packages may use slightly different quartile conventions, so state the method used in formal work. Always check source data, units, rounding and discipline-specific requirements before using a result in assessed, published, regulated or high-stakes work.

Questions

Frequently asked questions

How is this result calculated?

IQR = Q3 u2212 Q1; quartiles are estimated by linear interpolation on sorted observations.

Can I use this result in formal academic or research work?

Use it as a transparent calculation aid, then verify the assumptions, units, rounding and any institution-, journal- or field-specific requirements before formal use.