PixelTools

Aspect Ratio Calculator

Reduces any resolution down to its simplest width:height ratio, like 16:9 or 4:3.

Why aspect ratio matters for cropping

Knowing a resolution's exact aspect ratio helps you crop or resize an image or video without introducing black bars or unwanted stretching — matching the target display or format's expected ratio.

Common ratios and where they show up

16:9 is standard widescreen video and most modern monitors; 4:3 was standard for older TVs and monitors; 21:9 (or wider) shows up in ultrawide monitors and cinematic video formats.

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PixelTools

Aspect Ratio Calculator

Reduces any resolution down to its simplest width:height ratio, like 16:9 or 4:3.

Width (px)

Height (px)

Aspect ratio

16:9

Common ratios: 16:9 (widescreen), 4:3 (older monitors/TVs), 21:9 (ultrawide).

What you entered

Width (px): 1920Height (px): 1080

1
Divide both dimensions by their GCD
1920:1080 ÷ GCD= 16:9

Result

Aspect ratio: 16:9

1920×1080 simplifies to an aspect ratio of 16:9.

Why aspect ratio matters for cropping

Knowing a resolution's exact aspect ratio helps you crop or resize an image or video without introducing black bars or unwanted stretching — matching the target display or format's expected ratio.

Common ratios and where they show up

16:9 is standard widescreen video and most modern monitors; 4:3 was standard for older TVs and monitors; 21:9 (or wider) shows up in ultrawide monitors and cinematic video formats.