---
id: combo-charts
title: Combo Charts
description: Column charts are useful for visually comparing the number of events that have occurred.
slug: /help/docs/dashboards/panels/combo-charts/
canonical: https://www.sumologic.com/help/docs/dashboards/panels/combo-charts/
---
import useBaseUrl from '@docusaurus/useBaseUrl';
Combo charts have a secondary vertical axis allowing you to view two aggregates on the same chart. A common combo chart is a bar or column chart with a secondary vertical axis as a separate line as a comparison.
For example, say we're running a query like:
```sumo
_sourceCategory=*apache*
| parse "HTTP/1.1\" * * * " as status_code, size, referrer
| timeslice 5m
| avg(size), count by _timeslice
```
Generally, this query would produce a bar or column chart that looks a bit like this:
})
With a combo chart, you can set the `_count` to display as a line chart on a second Y axis. You will be able to see the number of requests over time from `_count`, against the average number of bytes per request from `_avg`.
})
To create a Combo chart, your query needs to return at least two dimensions of aggregate data or time series. Our example is returning `_count` and `_avg`.
1. Secondary axes are configured in the [Display Overrides](./modify-chart.md) menu. Open the **Display Overrides** menu. In the above screenshot, it is surrounded by a red box.
1. Select a field or series name to use for the secondary axis from the **Query or series name** dropdown option. We selected `_count` and set an optional **Alias**.
1. Under **Style** is where you tell the panel how to display the data. Select **AxisYType** and set it to **Right Y-Axis**. If you select **Left Y-Axis** it will overlap with the existing aggregate data since it is by default on the left.
1. By default, the additional axis will display in the same chart type of the existing data, as set by the Chart Type you selected. In the example above we selected **Chart Type** and set it to **Line** so it is easier to visualize.
1. Continue to set any other [overrides](./modify-chart.md) you want and save or update the panel when finished.