Photo Aspect Ratio Calculator
Keep photos proportional when resizing for screens, social posts, wallpapers or prints.
Use the free Photo Aspect Ratio Calculator
This tool runs locally in your browser. Your selected image is not uploaded to this website.
How the result works
Aspect ratio compares width with height. A 4:3 image remains 4:3 at 4000 × 3000, 1600 × 1200 or 800 × 600. Proportional resizing preserves that relationship and prevents faces or objects from looking stretched.
- Keep the aspect ratio locked while resizing
- Crop intentionally when changing formats
- Use the largest source before creating smaller versions
Common questions
How do I calculate aspect ratio?
Divide width and height by their greatest common divisor to produce a simplified ratio.
What happens if I change only one dimension?
If the other dimension is not adjusted proportionally, the image will stretch or compress.
What ratio is an iPhone photo?
Many iPhone camera photos use 4:3, but screenshots, portraits, panoramas and cropped images can use other ratios.