Making maps size question

[Prowlinger]

Ok the only options I can see on map sizes are 200x200 up to 500x500.

Now many maps (esp MP) from MoW are quite large. Is there a way to determine what their actual size is?

I am trying to see if they made multiple 500x500 maps and linked them together (how I wonder?) or what...

Some maps are just insanely long and narrow but well exceed the 500 range...

I made 1 map at 500x500 and it just looks tiny compared to the avg MoW map...

Any mappers out there know? (Sorry I cannot visit DMS here from work or would go there and ask)