How do I calculate an image aspect ratio?

Divide the width and height by their greatest common divisor. For example, 1920 by 1080 simplifies to 16 by 9.

How do I resize an image without stretching it?

Keep the original width-to-height ratio. When you choose a new width, calculate the height by multiplying the width by the original height divided by the original width.

What is the difference between aspect ratio and resolution?

Aspect ratio describes the shape of an image, while resolution describes its pixel dimensions. Different resolutions can share the same aspect ratio.

WIDTH ↔ HEIGHT ↔ RATIO

Image Aspect Ratio Calculator

Simplify any width and height to an aspect ratio, then calculate matching resize dimensions without stretching or squashing your image.

Calculate an aspect ratio

Enter an image’s width and height in whole pixels.

Width Height

Simplified aspect ratio 16:9 1.778:1 • Landscape

Resize with the same proportions

Change either value and PixGauge calculates the matching dimension automatically.

New width in pixels New height in pixels

1280 × 720 pixels Same 16:9 proportions—no stretching.

THE FORMULA

How aspect ratios work

aspect ratio = width ÷ height

An aspect ratio describes shape, not file size or image quality. A 1920 × 1080 image and a 3840 × 2160 image are both 16:9, even though the second has four times as many pixels.

To simplify a ratio, divide both dimensions by their greatest common divisor. For 1920 × 1080, that divisor is 120, producing 16:9.

CROP OR RESIZE?

Keep the shape to avoid distortion

Resizing to another size with the same ratio preserves the image’s proportions. Changing the ratio requires either cropping part of the image, adding borders, or stretching the content.

For example, a 3:2 camera photo does not fit an 8 × 10 inch frame’s 4:5 ratio exactly. A small crop or border is required.

COMMON QUESTIONS

Aspect-ratio FAQ

How do I find an image’s aspect ratio?

Enter its width and height above. PixGauge divides both values by their greatest common divisor to produce the simplest whole-number ratio.

Does aspect ratio affect image quality?

Not directly. Quality depends on pixel dimensions and the intended display or print size. Aspect ratio only describes the image’s shape.

Why does my image crop when I change ratios?

Two different shapes cannot fit each other without cropping, stretching, or leaving empty space. Cropping removes the excess while preserving natural proportions.