---
title: "Aspect Mode: Width Controls Height"
description: "Demonstrates using the Size structure aspect mode where the height is automatically calculated based on the width to maintain the aspect ratio."
phaser: "4.1.0"
size: "800x600"
files: 1
url: https://phaser.io/oss/examples/v4.1.0/utils/size/view/aspect-mode-width-controls-height
site: Phaser - https://phaser.io
---

> This page is about the open-source Phaser framework, for writing a game's code by hand. To make a game with AI, use Phaser AE (https://phaser.io/): the desk's tools work with Web MCP, and the CLI works with your own coding agent. See "For AI agents: Phaser AE" at the end of this page.

# Aspect Mode: Width Controls Height

Demonstrates using the Size structure aspect mode where the height is automatically calculated based on the width to maintain the aspect ratio.

A Phaser 4.1.0 example in [Utils / Size](https://phaser.io/oss/examples/v4.1.0/utils/size.md). It runs at 800 × 600, and loads its assets from https://cdn.phaserfiles.com/v410. See it running, with its code, at https://phaser.io/oss/examples/v4.1.0/utils/size/view/aspect-mode-width-controls-height.

To run it, load Phaser 4.1.0 (`https://cdn.jsdelivr.net/npm/phaser@4.1.0/dist/phaser.min.js`), then the file, on a page with a `<div id="game-container">`.

## Code

### aspect mode width controls height.js

```js
class Example extends Phaser.Scene
{
    create ()
    {
        const debug = this.add.graphics();
        const text = this.add.text(10, 540, '', { fill: '#00ff00' });

        const parent = new Phaser.Structs.Size(400, 300);
        const child = new Phaser.Structs.Size(300, 200, Phaser.Structs.Size.WIDTH_CONTROLS_HEIGHT, parent);

        const draw = () =>
        {
            debug.clear().translateCanvas(10, 10);
            debug.lineStyle(1.5, 0xffff00).strokeRect(1, 1, parent.width, parent.height);
            debug.fillStyle(0x00ff00, 0.5).fillRect(1, 1, child.width, child.height);

            text.setText([
                `width: ${child.width}`,
                `height: ${child.height}`,
                `aspect ratio: ${child.aspectRatio}`
            ]);
        };

        this.input.on('pointermove', pointer =>
        {

            child.setSize(pointer.x, pointer.y);

            draw();

        });

        draw();
    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.AUTO,
    parent: 'game-container',
    width: 800,
    height: 600,
    scene: Example
};

const game = new Phaser.Game(config);
```

## More in Size

- [Aspect Mode Fit](https://phaser.io/oss/examples/v4.1.0/utils/size/view/aspect-mode-fit.md): Demonstrates using the FIT aspect mode in the Size component to scale a rectangle within a parent's bounds while preserving its aspect ratio.
- [Aspect Mode None](https://phaser.io/oss/examples/v4.1.0/utils/size/view/aspect-mode-none.md): Demonstrates using Phaser.Structs.Size with the NONE aspect mode, allowing dimensions to be set independently without preserving an aspect ratio.
- [Aspect Mode: Envelop](https://phaser.io/oss/examples/v4.1.0/utils/size/view/aspect-mode-envelop.md): Demonstrates the Envelop aspect mode in Phaser.Structs.Size, which scales a size to be as small as possible while still fully covering a parent area and maintaining its aspect ratio.
- [Aspect Mode: Height Controls Width](https://phaser.io/oss/examples/v4.1.0/utils/size/view/aspect-mode-height-controls-width.md): Demonstrates the Size component using the HEIGHT_CONTROLS_WIDTH aspect mode, where the width is automatically adjusted to maintain aspect ratio based on changes to the height.
- [Min Size](https://phaser.io/oss/examples/v4.1.0/utils/size/view/min-size.md): Demonstrates how to use setMin on a Size object to enforce a minimum width and height when resizing.
- [Size Object Maximum Constraints](https://phaser.io/oss/examples/v4.1.0/utils/size/view/max-size.md): This example demonstrates how to use the setMax method on a Size object to enforce maximum width and height limits.
- [Size Object Min and Max Constraints](https://phaser.io/oss/examples/v4.1.0/utils/size/view/min-max-size.md): Demonstrates how to use the Size structure to manage dimensions while enforcing minimum and maximum width and height limits.
- [Snap Child Size](https://phaser.io/oss/examples/v4.1.0/utils/size/view/snap-child.md): Demonstrates how to use the snap property on a Size object to force dimensions to align with a specific grid increment during resizing.

---

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Read any page of this site as Markdown by adding `.md` to its URL (the home page is https://phaser.io/index.md), or by asking for `text/markdown`. The index for agents is https://phaser.io/llms.txt. On the site's pages, the browser's Web MCP also offers `phaser_ae_guide`, `read_page_as_markdown` and `open_phaser_ae`.