Visualization types

Line Graph

• Distribution

Also known as: line chart

A line graph is a chart that displays a series of data points connected by line segments.

Line graphs can be used to show how data changes over time and are often used to communicate trends, such as how household income changes each year. The x-axis can display continuous or discrete data such as days, years, or categories, and the y-axis is typically a continuous variable but can also be discrete. Line graphs can also be used to compare multiple trend lines, whereas bar charts can only represent one trend line.

Examples

Guidance

In addition to the guidance provided in this section, relevant guidance can also be found in the Agency Logo, Axes, Colors, Grids, Labels, Legends, Source, Titles, Typography sections.

Requirements

Always

• Start the y-axis at zero.

• Label each line if there is more than one line.

• Ensure that each line is legible.

Never

• Never use a legend for a graph with a single line.

Recommendations

Not Recommended

• Don’t use horizontal lines unless conveying exact amounts.