Proportional Image Resize Calculator
Scale images up or down by percentage or custom constraints without distortion, stretching, or loss of proportional balance.
Proportional Scale Studio
Drop an image or enter your source dimensions to calculate resized resolutions and export in-browser.
Drag and drop an image here, or browse
100% private. Stays directly on your machine.
Rendered via client-side HTML5 Canvas. Zero server uploads.
How Proportional Resizing Works
When an image is scaled proportionally, both width and height are multiplied by the exact same scaling coefficient (k = Scale% / 100). This guarantees that the original aspect ratio (W / H) remains identical.
Downscaling 1920×1080 by 50% produces 960×540. The total pixel count drops by 75% (from 2.07 MP to 0.52 MP), dramatically improving web load speeds.
Scaling 1920×1080 to 200% yields 3840×2160 (4K UHD). The aspect ratio remains perfectly 16:9 while quadrupling canvas pixel area.
Specify a target width (e.g., maximum container width 800px) and let cross-multiplication determine the matching height to prevent layout shifts.