I am currently working on making a city world and got to thinking...
The world is set to a "large" size, meaning the height map is 2048x2048. I have found a thread about world sizes and lot amounts, and the question was if the size of the image in pixels equates to the size of the world in tiles. The overall answers seemed to suggest so, however, this makes me wonder how large the world is in terms of area.
My question here is: does one tile equal one square meter?
In other words, how large is the world in square miles or kilometers?

From what I've read and heard in tutorials on meshing, one "square" does equal one meter. I'm American and firmly imperial, so I have no concept of metric measurements, lol. I'm sure there's a meters/kilometers to miles converter out there.

There is. Just go to Google and search "unit converter". It will show a conversion calculator directly on the Google results page where you can choose to convert units of distance, speed, area, volume, ect.

Thank you for the confirmation, though.

So, the largest world size (2048x2048) is 1.27x1.27 miles, or 1.62 square miles.

It's very big and you have to make it all and make it run on your computer. You would be better off starting on something small.

Sims 3 is apparently 1 pixel per one square meter. The large map, 2048, based on the above 1.27 miles, Google says is 2.043 km.... Close enough, there's probably a few extra decimals in the 1.27 that would bring it up to 2.048 km, or 2048 meters.
I didn't know this information until just now looking up the conversion.

So, I guess a Tiny map, 256x256 pixels, is only 256 meters on a side, or 840 feet, approx.