conversion rate for a touch in local space and for an object in local space

Does anyone know the conversion rate for a finger touch in local space and an object in local space?

I am looking to see if there are conversion function from world space to object space. The problem I am having is that my finger touch is measured in screen space i.e. ((0,0) is the bottom left corner and (480, 320) is the upper right hand corner. In the game my X values spread from 0 to 1090, and the Y values go from 0 to 320. So basically speaking I am trying to get screen space and the World space to be 1:1 identical. I have tried camera.WorldToScreenPoint() without luck. It doesn't seem to want to update properly.

Any and all help will be appreciated.

There is no conversion rate. It depends how far away your object is from the camera, and how much depth of field your camera has. There is no direct correlation between pixels and world units, though the Camera class has various functions that let you convert from screen units to world units easily.