> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cube.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Axes

> Configure axis titles, grid lines, label formatting, dual Y-axis, and reference lines.

The **Axes** section in the Style tab controls the appearance and behavior of the X axis and Y axis (or left and right Y axes in dual-axis charts). Most axis settings are available for all Vega-based chart types (bar, line, area, scatter, heatmap).

## X axis

| Setting          | Description                                            |
| ---------------- | ------------------------------------------------------ |
| **Show axis**    | Toggle the X axis on or off                            |
| **Title**        | Custom axis label — leave blank to hide the axis title |
| **Grid lines**   | Toggle grid lines perpendicular to the X axis          |
| **Labels**       | Toggle axis tick labels                                |
| **Label angle**  | Rotate axis labels (useful for long category names)    |
| **Label format** | Number or date format applied to axis labels           |

## Y axis (left)

| Setting          | Description                                                      |
| ---------------- | ---------------------------------------------------------------- |
| **Show axis**    | Toggle the Y axis on or off                                      |
| **Title**        | Custom axis label                                                |
| **Grid lines**   | Toggle horizontal grid lines                                     |
| **Labels**       | Toggle axis tick labels                                          |
| **Label format** | Number format applied to axis labels (e.g. `$,.0f` for currency) |
| **Min / Max**    | Override the axis scale minimum and maximum values               |

## Dual Y axis (right axis)

Add a second Y axis on the right side of the chart to plot a series on a different scale. This is useful for combining measures with different units or magnitudes — for example, showing order count on the left axis and average order value on the right.

To use the right axis:

1. In the **Series configuration** for a specific series, change the **Y axis** assignment from **Left** to **Right**.
2. The right axis settings appear in the Style tab — configure its title, labels, and scale independently from the left axis.

## Reference lines

Add horizontal reference lines to mark a target, threshold, or benchmark value. Reference lines appear at a fixed Y value across the full width of the chart.

To add a reference line:

1. In the **Y axis** section of the Style tab, click **Add reference line**.
2. Set the **Value** — the Y position of the line.
3. Optionally set a **Label** that appears next to the line.
4. Configure **Color** and **Style** (solid, dashed, or dotted).

You can add multiple reference lines to the same axis. Each is configured independently.

<Note>
  Reference lines are only available on the left Y axis. For right-axis reference lines, use a [custom Vega-Lite spec](/docs/explore-analyze/charts/custom).
</Note>