How to have a grid detect which square a player is in, in unity 2D

The gist of this is i want to have a very large grid with 1x1 squares and i want to be able to detect which grid in particular the player is closest to, say if the player is in the middle of two squares on the grid it will assume the player is in that one

I thought a way of doing it would be to use hundereds of box colliders but thought there may be an easier way of going about it, any help would be much appreciated

you would convert the world coordinates to your grid coordinates.

so as you have a nice easy 1x1 grid if the player is at (1,0,4) in world coordinates then you know they are in the grid (1,4) if the grid lines up the world coordinates if not then you would add some offset to the code

if they are at (1.4,0,5.6) then you would round it to the nearest integer so the player is (1,6) on your grid

the easiest way to do this is to have the center of your zero square centered at 0,0,0 on the world coordinates.