What is an aspect ratio?

It is the proportional relationship between an image's width and its height. For example, old TVs were 4:3, while modern HD screens are 16:9.

Does this tool actually crop my image?

No, this is purely a mathematical calculator to help you figure out the correct numbers before you resize an image in software like Photoshop.

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Image Tools

Calculate pixel dimensions for images and videos while maintaining perfect aspect ratios.

Last updated July 31, 2026

1Select a preset aspect ratio (like 16:9) or type your original Width and Height.
2Type your desired new Width in the 'New Dimensions' box.
3The corresponding Height will automatically calculate to prevent stretching.

Resizing Photos

Find out exactly what height an image needs to be when you restrict its width to 800px on your blog.

Video Editing

Scale a 4K (3840x2160) video down to 1080p or 720p without distorting the frame.