How to Create a Histogram Chart

A histogram is a chart that shows the frequency of different occurrences in visual form. It is useful for comparing the number of times different events occur such as the number of times a football team passes vs. the number of times it runs, the number of students who got different letter grades on a test, or the heights of students in a particular grade.

Instructions

1. Determine the categories that you will be tracking and write those on the horizontal axis. For example, if you were tracking a baseball player's pitches, you might have fastballs, curve balls, changeups and sliders.

2. Count the number of occurrences for each category. For example, in a game you might observe 20 fastballs, 30 curve balls, 15 changeups and 10 sliders.

3. Determine the scale for the vertical axis. The scale is how many occurrences are represented by one unit on the vertical axis. For example, if your histogram chart will be 10 boxes high and your largest category has 90 occurrences, you might set the scale to be one box is equivalent to 10 occurrences.

4. Draw a bar extending upward from the horizontal axis above each category to represent the number of occurrences for that category. For example, if your scale for the vertical axis was one box for every five occurrences, you would draw a bar four boxes high above "fastballs," six boxes high above "curve balls," three boxes high above "changeups" and two boxes high above "sliders."

Tips & Warnings

• Always remember to label your horizontal and vertical axis so viewers understand the chart.

References

• Making Histograms
• Histograms