Statistics chart and graph makers
Chart makers and frequency-table tools for turning raw numbers into a picture: histograms, box plots, dot plots, stem-and-leaf plots, pie charts, Venn diagrams and scatter plots. Each draws the chart and shows the table or calculation behind it, so you can copy either into an assignment or report.
Which calculator do I need?
| You have or want | Use |
|---|---|
| The shape of one set of numbers, with bars for each range | Histogram maker |
| Compare the spread of several groups side by side | Box plot calculator |
| A small dataset where every value should stay visible | Stem-and-leaf plot |
| Shares of a whole, such as survey answers by category | Pie chart calculator |
| The relationship between two variables | Scatter plot maker |
| A frequency table with relative and cumulative columns | Frequency distribution calculator |
| Your data plotted against mean ± 1, 2, 3 SD | Standard deviation graph |
| A normal curve from a mean and standard deviation | Bell curve generator |
Distribution charts
Charts that show how the values of one variable are spread out.
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Histogram maker
A histogram from pasted data, with counts on every bar and a fitted normal curve.
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Histogram calculator
Bins by Sturges, square-root, Scott or Freedman–Diaconis, with the frequency table and histogram.
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Box plot calculator
Box-and-whisker plots for one or several data sets, with quartiles, fences and outliers.
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Dot plot calculator
A stacked dot plot of your data, with counts, the mode, mean and median.
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Stem-and-leaf plot calculator
Stem-and-leaf displays with any leaf unit, split stems, or two data sets back to back.
Frequency tables
The tables most charts are built from, and the class widths and sorting that go into them.
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Frequency distribution calculator
Grouped or ungrouped frequency tables with relative, cumulative and cumulative relative frequency.
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Relative frequency calculator
Relative and cumulative relative frequencies from raw values or category counts.
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Frequency polygon calculator
Class midpoints and frequencies plotted as a closed frequency polygon, from data or a class table.
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Class width calculator
Class width from the range and number of classes, with the class limits and boundaries.
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Data analysis calculator
Frequency table, histogram and ogives from raw data, with the grouped mean, median and mode.
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Least to greatest calculator
Put fractions, decimals, negatives and percentages in order, least to greatest or the reverse.
Categories and relationships
Charts for shares of a whole, overlapping sets and pairs of variables.
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Pie chart calculator
Percentages and central angles in degrees for each category, drawn as a pie chart.
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Venn diagram calculator
Two- or three-set Venn diagrams from counts or element lists, with every region filled in.
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Scatter plot maker
Plot x-y data with axis labels and a trend line, with the equation, r and R².
Standard deviation and the normal curve
Pictures of spread: your data against its SD bands, or a normal curve with shaded areas.
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Standard deviation graph
A histogram of your data with the fitted normal curve and ±1, 2 and 3 SD bands shaded.
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Bell curve generator
A normal curve drawn from any mean and SD, with the sigma bands shaded and labelled.
Picking the right chart
Start from the kind of data and the question.
- One numeric variable, many values. A histogram shows the overall shape: where values cluster, whether there is a long tail, whether there are two peaks. A box plot reduces the same data to five numbers and is better for comparing several groups at once.
- One numeric variable, few values. A dot plot or stem-and-leaf plot keeps every value visible, which a histogram loses.
- Categories. A pie chart works for a handful of parts of one whole. For many categories, or to compare counts, a bar chart reads more accurately.
- Two numeric variables. A scatter plot shows whether they move together; add a trend line to see the direction and strength.
How many bins?
A histogram’s shape depends on its class width. Too few bins hide detail; too many turn it into noise. Sturges’ rule suggests k = 1 + log₂ n classes. For 20 values that is 1 + 4.32 ≈ 5.3, so about 6 classes. If the data run from 12 to 71, the range of 59 divided by 6 gives 9.8, rounded up to a class width of 10, starting at 10 or 12. The class width calculator does this arithmetic and lists the class limits and boundaries; the histogram calculator compares Sturges with the square-root, Scott and Freedman–Diaconis rules.
Common mix-ups
- Histogram vs bar chart. Histogram bars touch because the classes are continuous ranges; bar chart bars are separate categories.
- Frequency vs relative frequency. Frequency is a count; relative frequency is that count divided by the total, which lets you compare groups of different sizes.
- Frequency polygon vs line graph. A frequency polygon joins class midpoints and closes at zero on both ends; it shows a distribution, not a change over time.