Line Charts

Line charts are ideal for showing trends and displaying quantitative data series over continuous intervals or a period of time. Line charts are useful for comparing data over time and for measuring data against a non-time dimension. Line charts don't require a zero baseline.

Line Chart
Multi Line Chart
Annotated Line Chart


  • Choose a time period that encompasses reference points that adds perspective to the data.
  • Always label your axes and include the units for the y-axis.
  • On the y-axis, choose increments that are easy to follow. All values on the y-axis must be divisible by the increment itself
  • When using a short period of time or a category x-axis, use the marker symbol (dot).
  • Display negative values below the zero baseline.
  • Start the y-axis at zero when you have values close to zero.


  • Don't shade below a line chart unless it has a zero baseline.
  • Don't use more than 5 to 6 data series when using multiple lines. More is not always better. Plot the data that helps you get your point across.
  • Don't use a double scale on the y-axis when comparing same data series.