How to display pictures' aspect ratios in a directory view?

[rsbrux]

Since I am trying to crop most of my photos to 16:9 (for display on my HTPC monitor) it would be helpful to have an overview of the aspect ratios of pictures in a given directory.
I couldn't find aspect ratio in Windows 10 properties and I haven't been able to get it in XnView MP's thumbnails. I do have a custom label in XnView MP displaying width, height and file size, but custom labels apparently can't do arithmetic (e.g. width/height) and I am too lazy to do the arithmetic in my head for each photo.
Does anyone know of a way to get such a directory view, whether in Windows Explorer, XnView MP or some other photo browser?

[jkm]

You can do this in XnViewMP. Here's how:

In the browser window, change to Details view. (View->View As->Details).
At the top of the file list, you'll see column headers. Right click on this, and you will see a menu presenting all the Columns/Headers available to you.
One of them is Ratio. Put a check mark next to it.

You can uncheck any columns you don't want to see, or add others.

The column headers can be dragged to reorder them.

You will have to be satisfied with the fact that 16:9 images are shown in the ratio column as 1.8. It's better than nothing. The app properly displays some ratios, like 4:3, and not others like 3:2 which is shown as 1.5. (You can request an enhancement to fix this in the Suggestions forum.)

You can also sort by the ratio column by clicking on its header, and that will have the effect of grouping like-ratio images together.

If you want to see Aspect Ratio in a thumbnails view, just put {Ratio} in one of your label lines. You must have missed this when constructing your custom labels. The >> button to the right of the label field gives you a menu to insert lots of things. Ratio is right on there, in the Image submenu.

Does this help?

[rsbrux]

Many thanks for the detailed explanation! That's just what I needed.
Ratio was already enabled, but so was everything else, which had pushed it off the right edge of the screen.
Apparently all columns are enabled by default. This is a bit annoying: I am rarely interested in more than a few items from the EXIF and IPTC properties, and it is painful to have to disable them one by one. Is there some better way?