How do I see the exact dimensions of my video clip?

My edit starts off with a screen split into two, then three, then four horizontally and so on, up to 23 different horizontal bars of different videos! My questions is, after I've cropped and zoomed the clip as I want it, is there anyway to set the dimensions (e.g. so that it's exactly 540 pixels high), and is there an exact way to place it say in the exact middle of the screen. Cropping and zooming currently mean that I'm using guesswork to do this - would appreciate any info. Even a way to tell the position of the clip in the movie window would help. All the best.

You'd have to do the math, I think.

What Jim said, probably. In Fusion you should be able to get it less painfully, by using expressions etc, but in Resolve side just take a calculator and punch in some numbers.

My edit starts off with a screen split into two, then three, then four horizontally and so on, up to 23 different horizontal bars of different videos! My questions is, after I've cropped and zoomed the clip as I want it, is there anyway to set the dimensions (e.g. so that it's exactly 540 pixels high), and is there an exact way to place it say in the exact middle of the screen. Cropping and zooming currently mean that I'm using guesswork to do this - would appreciate any info. Even a way to tell the position of the clip in the movie window would help. All the best.

If you went to Fusion you could get the exact control that you want. You can use expressions on a Merge or Transform node's Position controls to ensure that a given split takes up 1/X of the screen.

Clips can be added to Fusion either statically - dragging them from the Media Pool, or (if they're still images) loading them with loader nodes - or, if you want to be able to adjust their timing on an Edit timeline, they can reach Fusion via a Fusion Clip. The latter method would allow adjusting their exact duration and temporal position on a Timeline (as you're currently doing), then going into Fusion to achieve the split screen effects that you want.

A Fusion Clip is a type of nested timeline, and operates in most respects like a Timeline or Compound Clip. A Fusion Clip allows multiple simultaneous clips to be seen by a single Fusion composition, by virtue of each video layer using a separate MediaIn node on the Fusion page. For example, a Fusion Clip that contains 23 video layers will provide 23 MediaIn nodes to its associated Fusion composition, combined into a single composite node by 22 merge nodes. Expressions can be placed on the position parameters of those Merge nodes to do the split screening you want, and/or Transform nodes can be added before each Merge to do the same with a bit more control.

Thank you for all the very helpful comments - I'll try the fusion route.