Aspect Ratio Calculator
Two modes, instant results. Enter width and height to get the simplified ratio plus total pixels and megapixels; or enter a ratio with one side to get the matching dimension for print, video or design.
How to calculate aspect ratios
- 01Choose a mode: from dimensions, or from a ratio.
- 02Enter your numbers - results update as you type.
- 03Copy the ratio or the computed dimension into your project.
Calculator features
Dimensions to ratio, or ratio plus one side to the missing dimension - both one click away.
Total pixels and megapixels appear alongside the ratio, handy for camera and export comparisons.
16:9, 9:16, 4:3, 3:4, 1:1 and 21:9 built in, plus a custom ratio field for anything else.
Related free tools
Frequently asked questions
What aspect ratio is 1920x1080?+
16:9. Enter any size and the calculator reduces it to the simplest whole-number ratio automatically.
How do I calculate the aspect ratio of an image?+
Enter the image width and height in the calculator. It divides both values by their greatest common divisor and returns the simplest width-to-height ratio.
How do I get the height for a 16:9 video at 1280 wide?+
Switch to ratio mode, choose 16:9, enter 1280 as the width - the height (720) appears instantly.
Does it work for print sizes?+
Yes - any positive numbers work, including inches or centimeters for print layouts.
What is a 3:4 aspect ratio?+
A 3:4 ratio is a portrait frame that is three units wide and four units tall, such as 1080x1440.
Related articles
How to Calculate Aspect Ratio
Learn how to calculate aspect ratio from width and height, find missing dimensions for 16:9 or 9:16 video, and choose the right frame for images.
How to Resize an Image Online
Learn how to resize an image online to exact pixel dimensions, keep the aspect ratio, and prepare JPG, PNG, or WebP files for blogs and social posts.
How to Resize a Video Online
Learn how to resize a video online for 16:9, 9:16, square, or custom dimensions while keeping the aspect ratio for social posts and uploads.