Utility PlatformPractical online tools

Aspect Ratio Calculator

Find the simplified ratio of an image, video or screen, or calculate a missing dimension while keeping proportions intact.

Designed for practical resizing.Enter dimensions to find the exact ratio, then use a preset or custom ratio to calculate a matching width or height.

Find an aspect ratio

Find a missing dimension

Choose a ratio and enter either the width or height. The other dimension is calculated proportionally.

Resize while keeping the original ratio

Visual preview

16:9
16:9

Widescreen shape. The preview is illustrative and not a pixel-perfect rendering of your original file.

Common aspect ratios

  • 16:9 — widescreen video and modern displays
  • 9:16 — vertical video
  • 1:1 — square images
  • 4:3 — classic display and photo formats
  • 3:2 — common photography format

How it works

The calculator finds the greatest common divisor of the width and height, then divides both values by it to produce the simplest whole-number ratio.

Good for

  • Image and thumbnail sizing
  • Video export dimensions
  • Website and responsive design
  • Social media graphics

Frequently asked questions

Aspect ratio describes the proportional relationship between width and height, written as two numbers such as 16:9. It describes shape rather than physical size.
Enter the width and height. The calculator finds their greatest common divisor and divides both values by it. For example, 1920 × 1080 becomes 16:9.
Keep the original width-to-height ratio and change only one target dimension. The calculator computes the matching other dimension.
Yes. Both values divide by 120, producing 16 × 9. Other dimensions may be close to a common ratio without reducing to exactly the same whole-number ratio.

Method & notes

Ratio calculations use positive numeric dimensions and integer greatest-common-divisor reduction. Missing dimensions are calculated from proportional multiplication and rounded to the nearest whole pixel. The tool does not inspect or upload image files.

Explore more Digital & Developer tools for text and web-development utilities.