Local · Private · Free

Aspect Ratio Calculator

Lock a ratio and solve the missing width or height, simplify any size with GCD, and scale with video, screen & social presets. Runs live, on your device.

Aspect ratio

Ratio width

Ratio height

Dimensions (pixels) 16 : 9

Width

Height

Ratio locked. Edit width or height and the other follows. Click the lock to free both and read off the ratio instead.

Calculated locally. Nothing is sent anywhere.

Preview

16:9

Presets

Common ratios

Video & screen

Social & photo

Exact ratios, simplified automatically

Enter any width and height and the calculator reduces it to its simplest whole-number ratio using the greatest common divisor. So 1920×1080 reads as 16:9 and 2560×1600 reads as 16:10. Lock the ratio to resize without distortion, or unlock to discover the ratio of a size you already have. It runs entirely in your browser, free forever.

About Aspect Ratio Calculator

Aspect Ratio Calculator is a free, private productivity tool that runs entirely in your web browser. It lets you solve width or height for any aspect ratio, with screen and video presets built in. Everything happens locally on your device: your data is never uploaded to a server, no sign-up or installation is required, and it keeps working offline. It covers aspect ratio, resolution, 16:9, dimensions and more. Like every free tool by Digital Heroes, it is 100% free with no limits.

What you can do

Lock any aspect ratio (16:9, 4:3, 1:1, 21:9 and more) and solve the missing width or height instantly.

Simplify any width × height pair to its lowest whole-number ratio using GCD. For example, 1920×1080 becomes 16:9.

Apply one-click presets for common video resolutions (1080p, 4K, DCI), social sizes (Instagram, YouTube, LinkedIn) and screen formats.

Toggle between landscape and portrait and watch dimensions swap automatically without distortion.

Preview the exact visual shape of any ratio in a live scaled rectangle that updates as you type.

Read off the decimal ratio and total megapixel count alongside the simplified ratio in a single result panel.

How to use Aspect Ratio Calculator

Open Aspect Ratio Calculator in your browser. No signup needed.

Enter your ratio in the Ratio width and Ratio height fields, or click a preset chip.

Type a width or height in the Dimensions section. The locked dimension updates automatically.

Toggle the lock button to switch between solving a dimension and measuring the ratio of a known size.

Frequently asked questions

Is Aspect Ratio Calculator free?

Yes. Aspect Ratio Calculator is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. Aspect Ratio Calculator runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. It is a Progressive Web App: once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does Aspect Ratio Calculator do?

It lets you solve width or height for any aspect ratio, simplify any resolution to its lowest ratio using GCD, and apply video, screen and social presets in one click.