Calculate aspect ratios and scale image dimensions proportionally. Perfect for maintaining aspect ratios when resizing images for web, video, or print.
Last updated: March 2026 | By Patchworkr Team
Enter either width or height to calculate the other dimension
Aspect ratio is the proportional relationship between an image's width and height, expressed as two numbers separated by a colon (e.g., 16:9). It describes the shape of the image, independent of its actual size.
Maintaining the correct aspect ratio is crucial when resizing images. If you change one dimension without proportionally adjusting the other, the image becomes distorted—stretched or squashed. For example, a 1920×1080 image has a 16:9 ratio. If you resize it to 1280 pixels wide, the height must be 720 pixels to maintain the 16:9 ratio.
Different media have standard aspect ratios: 16:9 for modern video and TV, 4:3 for traditional television, 3:2 for most DSLR cameras, 1:1 for Instagram posts, and 21:9 for ultrawide monitors and cinematic content.
To maintain aspect ratio when resizing:
Find the aspect ratio of a 1920×1080 image and scale it to 1280px wide:
The image will appear distorted—either stretched horizontally or vertically. People look unnaturally wide or tall, circles become ovals, and the image loses its intended proportions. Always maintain aspect ratio unless distortion is your creative intent.
Yes! Cropping removes parts of the image to achieve a different aspect ratio. For example, you can crop a 3:2 photo to 1:1 for Instagram. Unlike scaling, cropping changes composition but maintains image quality.
16:9 (1.778:1) is wider and standard for modern video/TV. 16:10 (1.6:1) is slightly taller, common for computer monitors and tablets. The difference is subtle but affects how much vertical content fits on screen.
21:9 is also called 2.39:1 or "cinemascope." Both describe the same ratio but in different forms. The first reduces to simplest terms, the second expresses width relative to 1 unit of height.
Downscaling (making smaller) preserves quality well. Upscaling (making larger) reduces quality—you can't add detail that wasn't captured. If you must upscale, use AI upscalers or limit increases to 150-200% maximum.
Instagram posts: 1:1 (square) or 4:5. Stories: 9:16 (vertical). Facebook: 1.91:1 (horizontal). YouTube: 16:9. Twitter: 2:1 or 16:9. Each platform has optimal ratios for best presentation.
The calculator shows the simplest form. For example, 1920:1080 simplifies to 16:9, not 32:18 or 160:90. Using the GCD ensures the smallest whole numbers that maintain the exact ratio.
There's no single standard—it depends on medium. Photography: 3:2 or 4:3. Modern video: 16:9. Cinema: 2.39:1. Prints: varies (4×6 is 3:2, 8×10 is 5:4). Choose based on your output medium.
Related Tools