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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.

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.

Quartile 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.