Aspect Ratio Calculator
Enter a width and height to calculate the simplified aspect ratio (e.g., 1920x1080 gives 16:9), or enter an aspect ratio and one dimension to calculate the missing dimension. The calculator supports two modes: ratio detection and dimension calculation.
Aspect ratios are fundamental in video production, photography, web design, and display technology. Common ratios include 16:9 (widescreen video, most monitors), 4:3 (classic TV, iPad), 1:1 (Instagram square), 9:16 (vertical video, Stories/Reels), and 21:9 (ultrawide cinema).
This tool is useful for resizing images without distortion, calculating video dimensions for different platforms, choosing monitor sizes, and ensuring design assets maintain their proportions.
By The Paper Room Editorial Team — Converter Tools
Frequently asked questions
How is the aspect ratio simplified?▼
The tool divides both width and height by their greatest common divisor (GCD). For example, 1920 and 1080 share a GCD of 120, so 1920/120 : 1080/120 = 16:9.
What are common aspect ratios?▼
16:9 (widescreen, YouTube, most TVs), 4:3 (classic TV, presentations), 1:1 (Instagram square), 9:16 (TikTok, Reels, Stories), 21:9 (ultrawide cinema), 3:2 (DSLR photos), and 2:1 (some mobile devices).
How do I find the width if I know the height and ratio?▼
Switch to dimension calculation mode, enter the ratio (e.g. 16:9) and the known height, and the tool calculates the width. The formula is: width = height x (ratio width / ratio height).