Largest level size?

What is the max size of a level in UE4, before the engine starts running into issues with collisions and physics, and whatever else ? (and that’s without any origin re-basing or world composition involved)

5km5km5km is the maximum size without any tricks like origin rebasing or level streaming.

Source: Which is the largest maximum size of land? - General Discussion - Unreal Engine Forums

Looks like it’s 20km based on the source code:

#define WORLD_MAX 2097152.0 /* Maximum size of the world */

Now the question is if it’s +/-20 km or +/-10km ?

The maximum size where things will still work well is smaller than the maximum size that the editor will limit you to

Ok, but what is it then?

My levels are huge and things have never been glitchy, I don’t understand why though. Some of them are larger than 20km that’s for sure. However those levels are in space where it’s mostly empty so maybe that’s why.

If you read the post, it’s 500k units, since each unit equals 1cm, that’s 5km