Enter any two values — width, height, or ratio — and the third fills in instantly. Includes 12 presets, standard resolutions, and a live visual preview.
16:9, and 800 × 600 simplifies to 4:3.width × ratio_H ÷ ratio_W. Calculated fields are highlighted in amber so you know which value was derived.16:9 for standard YouTube videos — recommended at 1920×1080 (Full HD) or 3840×2160 (4K). For YouTube Shorts, Reels, and TikTok, use 9:16 vertical at 1080×1920.1:1 (square) or 4:5 (portrait). Stories and Reels use 9:16. Twitter/X headers use roughly 3:1. Facebook cover photos are approximately 820:312.16:9 (1.78:1) is the universal standard for TV, online video, and most monitors. 16:10 (1.6:1) is slightly taller — common in older MacBooks and professional monitors — giving a bit more vertical space for documents and code. Most modern content targets 16:9.