PivoGraph
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Free online graph maker

Box plot maker

A box plot summarizes each group with its median, the middle half of the data and the overall spread, and draws outliers one by one. PivoGraph makes box and whisker plots from raw values, one group per column, with your choice of whisker definition and the option to plot every data point on top.

Make a box plot Opens the editor with sample data you can replace. No sign-up; your data stays on your device.
Box Plot of p-tau181 Levels across Cohorts
Example: Box Plot of p-tau181 Levels across Cohorts

The data you need

A Column table with one group per column and one value per row. Groups can have different numbers of values, and empty cells are skipped. Type or paste the values, or import them with File → Import Data (CSV).

Whiskers and what they mean

Choose the whiskers under Plot in Format Plot:

Option Whiskers reach
Tukey The most extreme values within 1.5 × IQR of the box; values beyond are drawn as points
Min to Max The smallest and largest value
10-90 percentile (also 5-95, 2.5-97.5, 1-99) The chosen percentiles; values outside are drawn as points

Quartiles and percentiles use the (n + 1)p rule, the same definition as R's quantile(type = 6), and are compared value by value with R on the validation page.

What you can adjust

  • Bars and boxes in Format Graph: the fill and border of the boxes and the Whisker ends.
  • Symbols: tick this card in Format Graph to plot every data point over the boxes.
  • Flip XY in Format Plot draws the boxes horizontally.

Statistics on the same graph

Compare the groups with a t-test, a Mann–Whitney test or a one-way ANOVA, and place the results above the boxes as brackets with stars, as shown in How to add significance stars to a graph. For skewed data, the Kruskal–Wallis test with Dunn's multiple comparisons is also available. Both nonparametric tests are checked against R: Mann–Whitney and Kruskal–Wallis.

Export for a journal

Export the figure as TIFF at up to 1200 dpi, or as PDF, EPS or SVG vector artwork; see How to export a 300 dpi TIFF figure for a journal. Describe the whiskers in the figure legend, for example "whiskers: Tukey (1.5 × IQR)".

Frequently asked questions

Is a box and whisker plot different from a box plot? No. They are two names for the same graph.

Box plot or bar graph? A bar graph with error bars summarizes each group with its mean. A box plot keeps skewness, unequal spread and outliers visible, which suits larger groups and data that are not normally distributed.

Can I turn the boxes into violins? Yes. Choose Violin plot in the same Box and violin group; see the violin plot maker.