Calculate aspect ratio and find matching dimensions
Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify
Clacify's Aspect Ratio Calculator finds the aspect ratio from any width and height (e.g. 1920×1080 = 16:9) and calculates matching dimensions for any given ratio. Use it to find the correct crop size for social media posts (Instagram 1:1 and 4:5, YouTube 16:9, TikTok 9:16), resize images while maintaining proportions, and calculate video output dimensions. Essential for video editors, web designers, and photographers.
16:9 means the width is 16 units for every 9 units of height. This is the standard widescreen format used for: YouTube, TV (HD and 4K), video calls (Zoom, Teams), most monitors, and smartphone horizontal video. Common 16:9 resolutions: 1280×720 (720p), 1920×1080 (1080p/Full HD), 3840×2160 (4K UHD).
Instagram recommends: Square posts: 1:1 (1080×1080px). Portrait posts: 4:5 (1080×1350px — shows larger in feed, performs better). Landscape: 1.91:1 (1080×566px). Stories and Reels: 9:16 (1080×1920px). For best reach, use 4:5 portrait for feed posts — they take up more screen space and get more visibility.