Practical limits of grid graph?

What are the practical limits of grid graph in questions of size?

I have some graphs around 200x200 to 400x400. My grid size is 1 unit (1m). I’m having a few glitching issues which I think are caused by thin walls (A* GraphUpdateScene elements).

I’m thinking of going down to 1/2 m which would quadruple the grid size (800x800) - over half a million cells. Would that be too much or is it “don’t worry about it until you hit several million cells” territory?


I have heard of games using a 1000x1000 grid graph. Though, I would usually recommend keeping it below 500x500 if you can.
A larger graph will use more memory, and pathfinding will be slower (it’s proportional to the number of nodes it has to search). You will have to profiler your game and see what works for you.