What are common photo aspect ratios?

3:2 is standard for 35mm film and most DSLR/mirrorless cameras. 4:3 is used by Micro Four Thirds and many phones. 16:9 is widescreen video. 1:1 is square (Instagram). 5:4 is a common print size (8×10 inches). 4:5 is Instagram portrait.

What happens when print and image aspect ratios differ?

If the print aspect ratio differs from the image, you must crop. For example, a 3:2 image (6000×4000) printed at 5:4 (8×10 inch) requires cropping 1000px from the long side — 500px from each side — leaving 5000×4000px (20MP). Always check the crop before ordering prints.

How do I calculate crop dimensions?

To crop to a target ratio, keep one dimension and recalculate the other. For 6000×4000 (3:2) to 5:4: the image (1.5) is wider than 5:4 (1.25), so keep the 4000px height and set the new width to 4000 × 5⁄4 = 5000px. That trims 1000px of width — 500px from each side — giving 5000×4000px.

Does aspect ratio affect composition?

Absolutely. Wider ratios (16:9, 2.35:1) emphasise horizontal landscapes and panoramic views. Square (1:1) creates balanced, symmetrical compositions. Portrait orientations (4:5, 2:3) suit vertical subjects. Choosing the right aspect ratio is a key composition decision.

Aspect Ratio Calculator — Convert & Crop

Convert between aspect ratios, work out the crop for a different print or display format, and resize proportionally.

Image Width

Pixel width of your source image (e.g. 6000 for a 24MP camera)

Image Height

Pixel height of your source image (e.g. 4000 for a 24MP camera)

Crop to Target RatioPick the print or display format to crop towards, or 'Same as image' to skip cropping

Target Width

Resize the cropped image to this output width (height follows automatically)

How We Calculate This

Aspect ratio is the proportional relationship between width and height:

Aspect Ratio

Ratio = width ÷ height (simplified using the greatest common divisor)

Cropping to a Target Ratio

If the image is wider than the target ratio, the height is kept and the width trimmed (new width = height × target ratio). If it is taller, the width is kept and the height trimmed (new height = width ÷ target ratio). The pixels removed are split evenly across the two edges.

Proportional Resize

New height = new width ÷ aspect ratio — scales the cropped image to your chosen output width without distortion.

Frequently Asked Questions

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Last updated: June 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.