Aspect Ratio Calculator
Calculate image, video and screen aspect ratios, simplify dimensions, and resize while preserving proportions.
Calculate and resize an aspect ratio
Enter width and height to simplify the ratio, then calculate a matching height or width without stretching the design.
What an aspect ratio calculator tells you
An aspect ratio describes the proportional relationship between width and height. A 1920 × 1080 canvas simplifies to 16:9, while 1080 × 1080 is 1:1. The ratio is independent of physical size: 1920 × 1080, 1280 × 720 and 640 × 360 all share the same 16:9 proportion.
How to resize without distortion
If the source width is W and height is H, the matching height for a new width N is N × H ÷ W. The matching width for a new height N is N × W ÷ H. This preserves geometry instead of stretching pixels or vectors.
Aspect ratio versus resolution
Aspect ratio is a proportion; resolution is the actual pixel count. Two images can share an aspect ratio but have very different sharpness, file size and suitability for print or high-density displays. Social platforms and ad networks may also crop assets even when the mathematical ratio is valid, so check the current placement specification before export.
Practical uses
Use the calculator for video frames, thumbnails, ad creative, presentation slides, responsive embeds, image crops and screen mockups. If both replacement dimensions are entered, the tool also flags proportional drift so you can decide whether cropping or intentional distortion is acceptable.