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Quartile Calculator

Find Q1, Q2 (median), Q3, the interquartile range and the five-number summary for box plots.

Enter values

Separate values with commas, spaces or new lines.

Results update as you type.

Result

Q1 / Q2 / Q3

25.5 / 40 / 42.5

IQR
17
Minimum
6
Maximum
49
Outliers (1.5 × IQR rule)
None

About the Quartile Calculator

Find Q1, Q2 (median), Q3, the interquartile range and the five-number summary for box plots.

Also known as: quartiles, five number summary, box plot calculator, q1 q3 calculator, lower and upper quartile.

How to use this calculator

  1. Enter data set.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

Q1 = 25th percentile · Q3 = 75th percentile (linear interpolation)

Worked example

Using the values pre-filled in the calculator above:

  • Data set: 6, 7, 15, 36, 39, 40, 41, 42, 43, 47, 49

the calculator returns:

  • Q1 / Q2 / Q3: 25.5 / 40 / 42.5
  • IQR: 17
  • Minimum: 6
  • Maximum: 49

Tips & common mistakes

  • Textbooks use several quartile methods; this calculator uses linear interpolation (the same as Excel’s QUARTILE.INC), so small data sets may differ slightly from a “median of halves” method.