keisoku

Box Plot Maker (from Raw Data)

Paste your raw numbers to compute the quartiles, IQR, and outliers, then draw a box plot automatically. The five-number summary is shown in a table too.

Input

Number data (separate with line breaks, commas, or spaces)

Values read as numbers: 20

Result

Median

15

6.9212.9518.9825.0231.0537.08Median 15Q1 12.75Q3 18

1st quartile Q1

12.75

3rd quartile Q3

18

Interquartile range IQR

5.25

Five-number summary, IQR, and outliers

ItemValue
Number of values20
Minimum9
1st quartile Q112.75
Median (Q2)15
3rd quartile Q318
Maximum35
Interquartile range IQR (Q3 − Q1)5.25
Lower fence Q1 − 1.5 × IQR4.875
Upper fence Q3 + 1.5 × IQR25.875
Lower whisker end9
Upper whisker end21
Number of outliers1

List of outliers

35

How it works

  • Paste number data separated by line breaks, commas, or spaces and the tool automatically computes the quartiles (Q1, median, Q3), the minimum and maximum, and the interquartile range (IQR), then draws a box plot.
  • Quartiles are calculated by linear interpolation over the sorted data (equivalent to the common spreadsheet QUARTILE.INC function). Note that the same data can yield slightly different values depending on the method used.
  • The box spans from the first quartile Q1 to the third quartile Q3, the bold line in the middle marks the median, and the whiskers extending left and right show the spread of the data excluding outliers.
  • Outliers are treated as values smaller than Q1 − 1.5 × IQR or larger than Q3 + 1.5 × IQR, and they are shown as individual points on the chart.
  • The whisker ends are drawn at the minimum and maximum values among the non-outlier data, so they may not match the overall minimum and maximum.
  • Handy when you want to see the spread, skew, and any outliers in test scores, measurements, survey scores, and similar data at a glance.