Understand the ratio
An aspect ratio compares width to height. For example, 16:9 means the width has 16 parts for every 9 parts of height. The actual pixel size can change while the shape stays proportional.
Aspect Ratio Calculator
Calculate a missing dimension or maintain aspect ratio for images and screens.
ratio
ratio
px
px
Aspect ratio result—
| Calculated dimension | — |
| Simplified ratio | — |
| Decimal ratio | — |
| Orientation | — |
Width—
Height—
Ratio W—
Ratio H—
Useful for images, videos, thumbnails, screens, and social-media graphics.
How it works
Resize without distortion
This Aspect Ratio Calculator helps keep width and height proportional when resizing images, videos, screens, thumbnails, banners, or design layouts.
You can find a missing width, find a missing height, or reduce any width-and-height pair into a simplified ratio. This helps prevent stretched or squashed visuals when preparing content for websites, video platforms, and social media.
Resize images cleanly
When you know the ratio and one dimension, the calculator finds the other dimension. This keeps images, thumbnails, graphics, and screenshots from becoming stretched or distorted.
Plan video formats
Common video and screen ratios include 16:9, 9:16, 4:3, and 1:1. Choosing the correct ratio helps content fit platforms, displays, and templates more accurately.
Simplify dimensions
If you already know width and height, the calculator can reduce them to the simplest ratio. For example, 1920 × 1080 simplifies to 16:9, making the format easier to recognize.
Frequently asked questions
Aspect ratio is the relationship between width and height. It does not describe the
exact size by itself; it describes the shape. A 1920×1080 video and a 1280×720 video are different sizes but
both use a 16:9 ratio.
Enter the ratio width and ratio height, then enter the known width. The calculator
uses the proportion height = width × ratio height ÷ ratio width to preserve the same shape.
Enter the ratio and known height. The calculator uses width = height × ratio
width ÷ ratio height. This is useful when a platform gives you a required height but you want the
matching width.
If width and height are changed without keeping the same ratio, the image can look
stretched, compressed, or distorted. Maintaining the ratio preserves the original proportions of the design
or photo.
Yes. It is useful for posts, reels, stories, banners, thumbnails, profile covers, and
ad creatives. You can test dimensions before exporting from a design tool.
A simplified ratio divides width and height by their greatest common factor. For
example, 3840×2160 becomes 16:9. This makes it easier to identify standard formats.