How Aspect Ratio Is Calculated
Aspect ratio = width / height, simplified to the smallest whole-number ratio using GCD. For example, 1920:1080 divides by GCD(1920,1080)=120 to give 16:9. The scaled height = (original height / original width) x new width, maintaining the ratio exactly.
Frequently Asked Questions
An aspect ratio is the proportional relationship between an image's width and height, expressed as width:height. For example, 16:9 means the image is 16 units wide for every 9 units tall. Aspect ratios are used to describe screens, photographs, videos, and print dimensions.
Common aspect ratios include: 16:9 (widescreen video, most monitors), 4:3 (older TVs, iPad), 1:1 (square, Instagram posts), 3:2 (35mm photography, most DSLRs), 2:1 (panoramic), 21:9 (ultrawide monitors), and 9:16 (vertical mobile video). Social media platforms have their own preferred ratios.
To resize while maintaining the aspect ratio, multiply both dimensions by the same scale factor. If the original is 1920x1080 and you want to scale to 50%: new width = 1920 x 0.5 = 960, new height = 1080 x 0.5 = 540. Alternatively, set one dimension and calculate the other: new height = (original height / original width) x new width.
16:9 is the standard widescreen format used for most modern televisions, monitors, and video content. 4:3 is the older television format and is still common for computer screens and tablets. 16:9 is mathematically equivalent to approximately 1.78:1, while 4:3 is approximately 1.33:1.
As of 2025, recommended ratios are: Instagram feed posts 1:1 (square) or 4:5, Stories and Reels 9:16, Facebook feed 16:9 or 1:1, Twitter/X 16:9 or 1:1, LinkedIn 1.91:1 for articles, YouTube thumbnails 16:9. Always check the platform's current guidelines as they change frequently.
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