For AI agents: the complete documentation index is available at /next/llms.txt, the full documentation bundle is available at /next/llms-full.txt, and this page is available as Markdown at /next/api/css/properties/aspect-ratio.md.
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  • aspect-ratio

    Introduction

    The aspect-ratio CSS property sets a preferred aspect-ratio for the box, which will be used in the calculation of auto sizes and some other layout functions.

    Examples

    Syntax

    aspect-ratio: 1 / 1;
    aspect-ratio: 16 / 9;
    aspect-ratio: 0.5;

    Values

    <ratio>

    The box's preferred aspect-ratio is the ratio of width to height. If the height and preceding slash are omitted, height defaults to 1. Size calculations involving aspect-ratio use the dimensions of the box specified by box-sizing.

    :::info The <ratio> CSS data type represents a ratio between two numbers. It consists of:

    • A positive <number> value
    • Followed by a forward slash ('/', Unicode U+002F SOLIDUS)
    • Followed by a second positive <number> value
    • Alternatively, a single positive <number> is allowed as a value :::

    Formal definition

    Initial valuehas no preferred aspect ratio
    Applies toall elements
    Inheritedno
    Animatable

    Formal syntax

    aspect-ratio = <number [0,]> [ / <number [0,]> ]

    Difference with the web

    mdn: aspect-ratio

    1. auto is not supported, one has no preferred aspect-ratio by default.

    Compatibility

    LCD tables only load in the browser

    Except as otherwise noted, this work is licensed under a Creative Commons Attribution 4.0 International License, and code samples are licensed under the Apache License 2.0.