What is aspect ratio?

Aspect ratio is the proportional relationship between width and height of an image or screen. Common ratios include 16:9 (widescreen), 4:3 (standard), and 1:1 (square).

How do I scale an image while keeping its ratio?

Enter the original width and height, then enter the new width or height. The calculator computes the missing dimension to maintain the exact ratio.

Aspect Ratio Calculator Online Free — Image & Video Ratios

How to Use the Aspect Ratio Calculator

Set original dimensions

Enter the original width and height of your image or video. Or click a common ratio preset like 16:9 or 4:3.

Enter one new dimension

Type a new width or height in the Scale To section. The other dimension is calculated automatically to maintain the ratio.

Use the result

The ratio, scaled dimensions, and a visual preview are displayed instantly.

Frequently Asked Questions

What is 16:9 aspect ratio used for?

16:9 is the standard widescreen ratio used for HD and 4K video, YouTube, most monitors, and modern TVs. Common resolutions: 1920×1080, 2560×1440, 3840×2160.

What aspect ratio should I use for social media?

Instagram posts: 1:1 or 4:5. Stories and Reels: 9:16. YouTube thumbnails: 16:9. Twitter images: 16:9. LinkedIn posts: 1.91:1.

What is 4:3 used for?

4:3 was the standard ratio for older TVs, computer monitors, and film. It's still used for some presentations (standard PowerPoint) and photography formats.

Aspect Ratio Calculator