- Height for target width
- Width for target height
Design utility
Aspect Ratio Calculator
Find the simplified ratio of an image or video and calculate proportional width or height for thumbnails, banners, screenshots, and responsive layouts.
Simplified ratio
The simplified ratio divides width and height by their greatest common divisor, turning 1920 by 1080 into 16:9.
Proportional resizing
To resize by width, multiply the target width by original height divided by original width. The reverse gives proportional width.
Rounding
Pixel dimensions may need rounding to whole numbers depending on your design tool, video encoder, or image export settings.
Aspect Ratio FAQ
Why do some tools show decimals?
Decimals describe the same relationship in another form. For example, 16:9 is approximately 1.7778.
Should I crop or resize?
Resize when you want to keep all content. Crop when you need a different ratio and are willing to remove edges.
Can this help with CSS?
Yes. The simplified ratio can be used with CSS aspect-ratio values such as 16 / 9.