The aspect ratio of an image is the proportional relationship between its width and its height. 

If the aspect ratio of an image differs from the print size selected in the shopping cart, the image will be cropped (the crop will need to be adjusted, depending on which part of the image you prefer to be printed).

There are plenty of different aspect ratios, I tried to collect/explain more about the most common ones below, taking a photo with the  aspect ratio of 3:2 as an example.

Here's a visual breakdown of 3:2 aspect ratio:

The image is three  "units" wide and two "units" in height.

My example image has 3:2 aspect ratio.

The dimensions of the image is 5630 × 3753 pixels. So one "unit" is 1876.66 pixels

3 x 1876.66 = 5630 pixels [width], 2 x 1876.66 = 3753 pixels [height] 

Print sizes for 3:2 aspect ratio 

4 x 6
6 x 9
8 x 12
10 x 15
12 x 18 
16 x 24 
20 x 30 
24 x 36

Print sizes for 7:5 aspect ratio

5 x 7
7 x 10
16 x 12

Print sizes for 5:4 aspect ratio

4 x 5
8 x 10
16 x 20 
24 x 30 

Print sizes for 1:1 aspect ratio

Basically all square sizes ;)

Comparison of those aspect ratios:

What about panoramic images? 

The aspect ratio differs, but the basic concept is that the image is at least twice as wide as it is high. So the image looks like a wide strip, the aspect ratio differs from 2:1 through 10:1 (if you want to cover the view up to 360 degrees).

To Crop or Not to Crop? 

You can crop photos and select only a certain area to print, even the photo doesn't require cropping, although if the photo does require cropping, you will need to move around the crop to fit the preferred area to print. If you cannot select the preferred area into the crop tool, you'll need to select a different print size. 

The problem starts, when you have a group photo and  people on the sides will be cut off, because of incompatible aspect ratios:

Do you have an opinion or suggestion? Feel free to share below: