What is my Form factor

That would be the tower and the manual is located here. The MB appears to be a Micro ATX. But that MB is proprietary so it would be a trick to replace it with a standard Micro ATX MB.

Thanks JOcean

I'm confused. When I originally bought it, it was described in the sale documentation as "Mini-Tower"

I was trying to get the manual and when I looked on Dell, all I could see was Tower/Small Form Factor/Micro.

I think what I have is SFF. It's definitely not a full tower. But I'm not sure.

If you go to the manual I linked to and see the dimensions of the tower, it is exactly what you posted. Remember that towers come in many sizes. Full towers, mini towers, micro towers, but all called towers. You have a mini tower, and the SFF dimensions are as follows and nowhere close to the dimensions you posted.

Height 290.06 mm (11.42 inches)
Width 92.71 mm (3.65 inches)
Depth 292.10 mm (11.50 inches)

On the other hand the dimensions for the mini tower are as follows and exactly what you posted.

Feature Specification
Height 350.52 mm (13.8 inches)
Width 154. mm (6.1 inches)
Depth 274.32 mm (10.8 inches)

Thanks for the clarification JOcean. Much appreciated.

I'm looking to replace my desktop, as the CPU does not meet Windows 11 requirements. I'm also considering building my own, hence the questions.

I like the size of the case, and would like to stick as close to that as possible in the future.

Given the dimensions that I gave, can you help me further by giving me the correct "description" to use for both the case and the motherboard, when I am shopping for self build parts?

Could you please upload a photo of your PC?  This will make clarification much easier.

The term "full tower" doesn't apply to Optiplex as it does larger towers, like may be Precision's.  The largest Optiplex's are mini towers.  The catch is the newer and newest ones, like the 3050, the "tower" or "mini tower" are a little smaller than they used to be and don't fit full size PSU's.  PSU's are a little harder to upgrade that way.

Thanks

bradthetechnut

Photos attached

Thanks for uploading photos.  You definitely have a mini tower.  Sometimes, one can abbreviate when parts searching.  We often refer mini tower as "MT."  But it may also be referred to simply as "tower" in Dell documentation.

Optiplex 3050 Spec Sheet 

Thanks bradthetechnut

Assuming I decide to self-build (and therefore will be moving away from Dell), what is the generic description of a case of this size and also what is the type of motherboard for that size?