Aspect Ratio Calculator
Simplify screen, image, and video ratios or scale a ratio to a new size
Calculation Steps
How Aspect Ratio Scaling Works
Aspect ratio keeps width and height proportional while dimensions change.
Simplified ratios
A ratio such as 1920:1080 reduces to 16:9 by dividing both sides by their greatest common divisor.
Proportional scaling
When the target width is known, divide it by the decimal ratio to get height. When height is known, multiply by the decimal ratio to get width.
Pixel rounding
Some target sizes produce fractional pixels. Round to the nearest whole pixel for exported assets and video encodes.
Aspect Ratio Examples
Common screen, video, and social formats use a small set of ratios.
1920 x 1080 video
1920 x 1080 simplifies to 16:9 and scales to 1280 x 720.
Vertical short video
A 9:16 ratio at 1920 px tall scales to 1080 x 1920.
Square creative
A 1:1 ratio keeps width and height equal at every size.
Aspect Ratio Calculator FAQ
Common questions about ratios, resolution scaling, and resizing without stretching.
What is aspect ratio?
Aspect ratio is the proportional relationship between width and height, usually written as width:height, such as 16:9.
How do I calculate an aspect ratio?
Divide the width and height by their greatest common divisor. For example, 1920:1080 simplifies to 16:9.
How do I resize without stretching?
Keep the same ratio. If you choose a new width, divide it by the decimal ratio to get the matching height.
What is the difference between 16:9 and 9:16?
16:9 is landscape widescreen, while 9:16 is the same relationship rotated vertically for phone-first video.
Why do scaled dimensions include decimals?
Some ratios do not land on whole pixels at every target size. Round to the nearest whole pixel when exporting or designing.