Is there a file size limit?

No practical limit for most operations.

Results are generated using standard algorithms for maximum accuracy.

best

Aspect Ratio Calculator — best

Calculate and scale aspect ratios for any resolution.

Common Presets

Width (px)

Height (px)

Type, paste, or upload your content.

Result appears instantly in your browser.

Copy the result or download your file.

Convert pixel values to em/rem units for CSS.

Resize images online to exact pixel dimensions or by percentage. Supports JPG, PNG, and WebP.

Calculate percentages easily: find X% of Y, percentage change, percentage difference, and more.