- Private: files never leave your device
- Free, no sign-up
- Fast, works offline once loaded
How to use Aspect Ratio Calculator
- Enter the original width and height. The simplified ratio appears instantly.
- Type a new width to get the matching height, or a new height to get the matching width.
- Use the preset buttons for common ratios such as 16:9 and 4:3.
About this tool
The aspect ratio is the proportional relationship between a picture's width and height. A 1920 by 1080 image has an aspect ratio of 16:9. This calculator simplifies any pair of numbers to its ratio, shows the decimal value and tells you whether it is landscape, portrait or square.
It also solves the common resizing problem: if you know the new width, it gives you the exact height that keeps the same shape, and the other way around. That keeps pictures, videos and designs from being stretched.
Frequently asked questions
How do I calculate the aspect ratio of an image?
Divide the width and height by their greatest common divisor. For example 1920 by 1080 simplifies to 16:9. The calculator does it for you.
How do I find the height for a new width?
Multiply the new width by the original height and divide by the original width, or just type it into the calculator.
What are the most common aspect ratios?
16:9 for video and screens, 4:3 for older screens and photos, 1:1 for square posts, 3:2 for photography and 9:16 for vertical video.
Is Aspect Ratio Calculator really free?
Yes. You can use Aspect Ratio Calculator as often as you like with no sign-up, no watermark and no daily limit.
Are my images uploaded to a server?
No. Aspect Ratio Calculator runs entirely in your web browser, so your files stay on your own device and are never sent to DEWANARO or anyone else.