Distance from the center of collider to the edge?

I am making shooting range game and i have a problem. I don’t know how to calcualte distance from the center of the collider to the edge. I want to know position where the bullet hit. How to do that?

I added screenshot for better explanation.

You could use Physics.Raycast to find this and then retrieve the position of the RaycastHit and compare it to the center of the collider.