Aspect Ratio Calculator

Simplified ratio, orientation, and megapixels from pixels.

What it does

Aspect ratios reduce pixel dimensions through their greatest common divisor: 1920 by 1080 shares 120, leaving the familiar 16:9. Orientation follows which side runs longer, with equal sides reading square.

The tool above takes width with height in pixels. It returns the simplified ratio with orientation and megapixels beside them.

The default 1920x1080 divides by 120 into 16:9 landscape at 2.07 MP. A square 1080x1080 reads 1:1 while portrait 1080x1920 flips to 9:16.

Pixel math follows W3C web definitions with MDN web documentation matching integer handling. Both treat ratio as shape alone, separate from physical size or density.

How to use

1. Enter the width in pixels.
2. Enter the height in pixels.
3. Read the ratio first for the shape.
4. Use orientation for layout decisions.
5. Use megapixels for print and sensor talk.

Formula

GCD

Greatest shared divisor simplifying the pair.

16:9

Widescreen shape from 1920x1080.

MP

Millions of pixels in the frame.

Whole pixels 1 to 100000 accepted; decimals round to nearest whole first. Ratio order always reads width then height.

Worked example

Reference table

Limits

• Shape only; physical size needs density.
• Whole pixels 1 to 100000.
• Anamorphic pixels stretch outside.
• Crop intent needs human eyes.

Common mistakes

• Reading 1920x1080 as 16:10 by habit.
• Swapping width with height.
• Confusing ratio with resolution size.
• Forgetting portrait flips the pair.
• Upscaling past sensor megapixels.

Try it yourself

Quick checks. Answers sit tucked under each question.

Questions

Sources

• W3C web standards
• MDN web docs

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