Aspect Ratio Calculator
Keep the shape, change the size. Find a missing dimension for a photo, video, illustration or screen.
Work here
Processed on your device. Input is never uploaded or saved.
Your result
How to use Aspect Ratio Calculator
- Enter your own input or try the example above.
- Choose the mode that matches your task. Results update as you edit; random generators run only when you choose Generate.
- Review the result, then copy or download it. Closing this tab discards the input.
Shape is a ratio
A 1920 × 1080 image and a 1280 × 720 image both use 16:9. The ratio describes shape, not sharpness or file size.
Resize proportionally
To preserve shape, new height = original height × new width ÷ original width. Round only the final pixel dimension; tiny rounding differences are normal.
Crop and fit are different
Matching a different target ratio requires cropping or empty margins. A proportional resize alone cannot fill a differently shaped frame without one of those tradeoffs.