To add a chart (you can only have one chart per report), use the Add Chart button (both in Classic and Lightning). Remember that your report must be in summary or matrix format before you can add charts:

The following are the settings that we can configure:

• Chart type: Decides on the type of display (such as bar, line, pie, funnel, scatter, and so on), which may depend on the report format.
• X-Axis/Y-Axis: Decides on which metrics to show in each axis by the record count, groupings, or summary fields.
• Combination Charts: We can plot additional values on the chart if the chart supports this feature (for example, we can add the number of employees of a given account, along with the number of locations where the account makes sales). When displaying values with different scales, you can add another y axis to the chart so that values are displayed accordingly and in a readable way:

• Grouping: If we have more than one grouping (for example, accounts by country and then by type), we can chart how each grouping contributes to the overall count:

• Values/wedges/segments: Which values and wedges are displayed depends on the kind of chart you use (pie, donut, or funnel chart).

• We can have up to 250 groups or 4,000 values in a chart. If we go over these limits, you will receive an error when running the report.
• If a running user loses access to a given field being used in a chart, another field of the same report may be used; otherwise, the record count is used.
• Numeric and currency fields should be rounded up to two decimal places, while percentages should be rounded to one decimal place.
• Negative values are displayed in bar and line charts but not in funnel/pie/donut charts.