Free Dot Plot Maker

Each dot is one value, placed above its spot on the number line. When values repeat, the dots stack, so the height of a stack is how many times that value occurs. The tallest stack is the mode, the spread of the dots is the range, and the outline of the stacks shows whether the data bunches in the middle, leans to one side or splits into two groups.

Gaps and loners matter as much as the crowd. A dot far away from the rest is an outlier, and a stretch of empty number line is a range of values nobody had. Because every value keeps its own dot, you can point at a single one, which a bar chart or a histogram cannot do.

To find the median, count the dots from either end to the middle one (or the middle two, when the count is even). This maker can draw the median as a dotted line and the mean as a dashed one, so you can see at a glance which way the data is skewed: the mean is pulled toward the long tail.

A line plot, as taught in elementary and middle school math, is a dot plot drawn with X marks, usually over whole numbers such as quiz scores or the number of pets per student. Switch the marks to X to draw one, and set the axis range to cover every possible score, such as 0 to 10.

A histogram answers the same question for big datasets. Once there are hundreds of values, individual dots stop being useful and bars are clearer: use the histogram maker. In between, the Bins mode here groups values into equal ranges and still stacks one dot per value, which keeps the count readable. For the exact digits of every value, try the stem and leaf plot maker.

A dot plot is not a scatter plot. A scatter plot places each point by two numbers, x and y, to show a relationship; a dot plot uses one number per value and stacks repeats. For pairs of numbers, use the scatter plot maker.

The strongest dot plots are about one value against all the others: a student's score in the class, tonight's delivery against the last month, the youngest champion in a sport's history. Highlight that value and it is drawn in the accent colour with its name and value above it, and the rest of the plot becomes its context.

Keep the reference lines to the ones your point needs: the median for a typical value, the mean when the average is the claim. If the chart is going on a phone screen, a slide or a video, choose the Compact canvas and a Large or Extra large text size, so the labels stay readable when the image is shrunk.