Aspect Ratio Calculator
Calculate and scale aspect ratios for images, video, and screens. Free, no signup, works in your browser.
16:9
Aspect Ratio16:9⎘
Decimal1.7778⎘
Dimensions1920 × 1080⎘
Scale to new size
Common Ratios
All calculations happen in your browser. No data is sent to any server.
About Aspect Ratio Calculator
This aspect ratio calculator determines the simplified ratio from any width and height dimensions and lets you scale to new sizes while maintaining the proportion. Enter dimensions like 1920×1080 and see the ratio (16:9), its decimal value, and a visual preview. Use the scale tool to find matching dimensions — for example, what width matches a height of 720 at 16:9. Common presets for widescreen, square, vertical video, and photography ratios are included.
Frequently Asked Questions
What is a 16:9 aspect ratio?
16:9 is the standard widescreen ratio used by most monitors, TVs, and YouTube videos. Common resolutions include 1920×1080 (Full HD), 2560×1440 (QHD), and 3840×2160 (4K).
How do I calculate the aspect ratio of an image?
Enter the width and height of your image. The tool divides both by their greatest common divisor to give you the simplified ratio. For example, 1920×1080 simplifies to 16:9.
What aspect ratio should I use for Instagram?
Instagram supports multiple ratios: 1:1 (square) for feed posts, 4:5 (portrait) for taller feed posts, 9:16 (vertical) for Stories and Reels, and 16:9 (landscape) for IGTV.