Aspect Ratio Calculator

Enter your image's current width and height.
Fill in the new width or the new height — the tool computes the other to keep the ratio.
Use presets for common ratios, or type your own.

Frequently Asked Questions

What does "16:9" mean?

The width is 16 units for every 9 units of height. The exact pixels depend on the scale (e.g. 1920×1080, 1280×720, 3840×2160).

Why does my image look stretched?

You changed only one dimension without keeping the ratio. Use this tool to compute the matching dimension first.

What is the difference between aspect ratio and resolution?

Aspect ratio is the proportional relationship (16:9); resolution is the actual pixel count (1920×1080). Many resolutions share one ratio.

Which ratio should I use for YouTube?

16:9 is standard for videos and the YouTube player. Shorts and vertical formats use 9:16.

Resize a 1920×1080 image to width 1280:

How to Use This Tool