What an aspect ratio tells you
A ratio compares width with height. A 3:2 image could be 3000 × 2000 pixels, 12 × 8 inches or any other pair with the same proportions. Changing size while preserving the ratio avoids distortion.
The ratio does not tell you resolution. Two files can both be 3:2 while one contains far more pixels and supports a larger print.
| Ratio | Example size | Common context |
|---|---|---|
| 3:2 | 4 × 6 or 12 × 18 in | Many camera images |
| 4:3 | 12 × 9 in | Some cameras and digital artwork |
| 4:5 | 8 × 10 or 16 × 20 in | Portrait and art prints |
| 1:1 | 8 × 8 or 12 × 12 in | Square prints |
| 1.414:1 | A4 or A3 | ISO A-series paper |
Why a print lab may crop your image
A 3:2 photograph matches a 4 × 6 inch print, but not an 8 × 10 inch print. If the lab fills the 8 × 10 page, part of the longer dimension must be removed. If it fits the whole image instead, empty borders appear on the shorter dimension.
Neither choice is mathematically wrong. The right choice depends on whether edge-to-edge output or the complete composition matters more.
Four ways to resolve a mismatch
Decide how to handle the ratio before final sharpening, adding text or calculating effective PPI. Cropping later can remove important pixels and move the composition.
- Crop deliberately to the paper ratio and reposition the subject.
- Fit the complete image and accept a border.
- Choose a print size that matches the source ratio.
- Extend the background carefully when the artwork allows it.
Resize without stretching
Lock proportions in the editing application or calculate the missing dimension from the original ratio. If a 16:9 image becomes 1200 pixels wide, its matching height is 675 pixels.
Do not type independent width and height values unless you intend to crop. Forcing a new ratio by scaling compresses or stretches the subject and is usually visible in faces, circles and typography.