> For the complete documentation index, see [llms.txt](https://docs.ideogram.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ideogram.ai/using-ideogram/generation-settings/aspect-ratio-and-dimensions.md).

# Aspect Ratio and Dimensions

Aspect ratio controls the shape of your generated image. Depending on the selected model, workflow, and generation size tier, you may see preset ratios, custom ratio controls, custom pixel dimensions, or resolution choices.

To select an aspect ratio or dimensions:

1. Open the Prompt Box.
2. Open **Aspect Ratio**, **Dimensions**, or **Resolution** depending on the current workflow.
3. Choose a preset or custom value supported by the selected model.

<figure><img src="/files/dkJNrZtJnfEkzER8z3G7" alt="Aspect ratio picker open in the prompt box with an Auto toggle, portrait and landscape preset lists, a square option, a live preview of a custom 15:14 ratio, and width and height sliders"><figcaption><p>The aspect ratio picker: <strong>Auto</strong>, presets, or a custom ratio with width and height sliders.</p></figcaption></figure>

## Common Preset Ratios

Ideogram commonly uses these preset ratios:

| Orientation | Presets                                            |
| ----------- | -------------------------------------------------- |
| Vertical    | `1:3`, `1:2`, `9:16`, `10:16`, `2:3`, `3:4`, `4:5` |
| Square      | `1:1`                                              |
| Horizontal  | `5:4`, `4:3`, `3:2`, `16:10`, `16:9`, `2:1`, `3:1` |

In API requests, aspect ratios use `x` separators, such as `16x9`, instead of `16:9`.

## Custom Dimensions and Resolution Tiers

Some models and plans support custom dimensions or resolution tiers. When custom dimensions are available, Ideogram may normalize your requested dimensions to a supported ratio, model size, or resolution tier.

Exact pixel outputs depend on the model, generation size tier, endpoint, and workflow. If docs need exact pixel tables, generate them from the same model catalog/config used by the app rather than maintaining a static table by hand.