Aspect Ratio Calculator
Calculate an aspect ratio, resize images and videos proportionally, and find dimensions for responsive layouts.
Original dimensions
Enter the width and height of your image, video, or layout.
Simplified aspect ratio
The simplified proportional relationship between width and height.
16:9
Decimal ratio
Original dimensions
Calculate proportional dimensions
Keep the same aspect ratio while changing one dimension.
Enter a width to calculate its matching height.
Enter a height to calculate its matching width.
What is an aspect ratio?
An aspect ratio describes the proportional relationship between a width and a height. For example, 1920 × 1080 pixels has a 16:9 ratio.
When resizing an image or video without distortion, preserve the ratio and calculate the other dimension proportionally.
Tip: aspect ratio alone does not determine image quality. Resolution, compression, and the display size also matter.