---
title: Aspect Ratio Calculator — Resize & Visualize Dimensions
url: https://varstatt.com/toolkit/ratio
description: Calculate aspect ratios, resize dimensions proportionally, and visualize common ratios like 16:9 and 4:3. Instant copy.
section: Developer Toolkit (https://varstatt.com/toolkit)
tags: media
related: Placeholder (https://varstatt.com/toolkit/placeholder), Aspect Ratio (https://varstatt.com/toolkit/ratio)
---
# Aspect Ratio Calculator

Calculate aspect ratios, resize dimensions proportionally, and visualize common ratios like 16:9 and 4:3. Instant copy.

## How It Works

1. **Enter a dimension** — Type a width or height in pixels. The tool calculates the other dimension when you select a ratio.
2. **Pick or calculate a ratio** — Click a preset ratio (16:9, 4:3, etc.) or enter both dimensions to see the simplified ratio.
3. **Copy and use** — Copy the ratio string or the calculated dimensions for your design, video, or responsive layout.

## FAQ

### How is the ratio simplified?

The tool finds the greatest common divisor (GCD) of width and height to reduce them to the smallest whole-number ratio.

### What's the most common screen ratio?

16:9 is the standard for monitors, TVs, and YouTube. 9:16 is standard for mobile/vertical video. 4:3 is common for older displays and presentations.

### Can I use this for images?

Yes. Enter your image dimensions to find the ratio, or pick a ratio and one dimension to calculate the other. Great for cropping, thumbnails, and responsive images. For generating placeholder images, try the [image placeholder generator](https://varstatt.com/toolkit/image-placeholder).

## Usage

This tool runs entirely in the browser — visit the URL above to use it.

Prefill inputs via URL parameters:

- `https://varstatt.com/toolkit/ratio?width=...&height=...`

## Related Tools

- [Placeholder](https://varstatt.com/toolkit/placeholder)
- [Aspect Ratio](https://varstatt.com/toolkit/ratio)