How long does it take to bake nevmesh of 15k x 15k plane size?

As mentioned in topic, I wanna know the determined time to wait for baking this size of plane which I have to use this size of plane because of the UI text issue. Do any one have experience about this?

The time will depend on the NavMesh baking settings and, of course, the performance of the CPU.
It is safe to assume that baking the NavMesh for a plane that large will not be instant.