About AspectKit

AspectKit is a free tool for working with aspect ratios and image dimensions. It does three things well: it resizes width and height while keeping the ratio locked, it simplifies any width × height into a clean ratio like 16:9, and it gives you one-tap pixel presets for the platforms people actually publish to — YouTube, Instagram, TikTok, X, and 4K video.

It was built to replace the clunky, decade-old calculators that still rank for these searches: no clutter, mobile-first, and genuinely fast.

Privacy

Every calculation runs entirely in your browser. We do not upload, store, or transmit any dimensions or images you enter. See our Privacy Policy for details on cookies and analytics.