Toolkit / Unit & Measurement Converters
Aspect Ratio Calculator
Calculate aspect ratios, missing width or height, and proportional sizes for images, videos, screens, and layouts.
Privacy note: Conversions are calculated in your browser and do not require personal information.
Limitations: Rounded pixel values can create a one-pixel difference in some layouts.
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How aspect ratio calculator works
Enter width and height or a target ratio, then calculate the missing dimension.
Keep proportions consistent when resizing thumbnails, videos, screenshots, and design frames.
Privacy
Conversions are calculated in your browser and do not require personal information.
Limitations
- Rounded pixel values can create a one-pixel difference in some layouts.
- Cropping may still be needed when the source and target ratios do not match.
- Device pixel ratio and CSS layout rules can affect how sizes appear on screen.
FAQs
What is an aspect ratio?
It is the proportional relationship between width and height, such as 16:9 or 1:1.
How do I resize without distortion?
Keep the same aspect ratio so width and height scale proportionally.
What is 16:9 used for?
16:9 is common for video, presentations, monitors, and many thumbnails.
What happens if ratios do not match?
You usually need to crop, add padding, or accept distortion.