Scale any image or video to the exact size you need
Original Dimensions
New Dimension
Enter the new width you want to scale to (px wide).
Result
Common Aspect Ratios
Tip: The simplified ratio divides both dimensions by their greatest common divisor (GCD). For example 1920×1080 simplifies to 16:9. Click any common ratio chip above to use that as your base dimensions.
The aspect ratio calculator lets you resize images, videos, or canvases while keeping their proportions perfectly intact. Enter the original width and height, choose whether you know the new width or height, and get the missing dimension in one click. It also simplifies your ratio to its lowest terms — such as 1920×1080 becoming 16:9 — so you can communicate dimensions clearly across any project.
An aspect ratio expresses the proportional relationship between a dimension's width and height, written as W:H. For example, 16:9 means for every 16 units of width there are 9 units of height. It stays constant regardless of the actual pixel size.
Divide the new width by the original width to get a scale factor, then multiply the original height by that same factor. This calculator does it automatically — just enter your original dimensions and the one new dimension you know.
Both the width and height are divided by their Greatest Common Divisor (GCD). For 1920×1080, the GCD is 120, giving 16:9. For 1024×768, the GCD is 256, giving 4:3.
Yes. The calculator works with any unit because aspect ratio is a pure proportion. Enter your dimensions in centimeters, inches, or any consistent unit and the result will be in that same unit.