Where on the body are coordinates taken from?

When using the GPS in Terraria your position in the world is displayed on the screen. However, it is unclear which point of the character’s body the coordinates are taken from.

Looking on the wiki page for the GPS yields no result, as the coordinates system isn’t even mentioned there.

Going to the far edges of a large world give X-coordinates of 8316’ West and 8314’ East, which suggests the X-coordinate is taken from the left hand side of the hit box. But, I still am no closer to knowing where the Y-coordinate is taken from.

Solution 1:

The Y-coordinate is taken at the character's feet. The depth displayed is the same as that shown by the Depth Meter which has a note that clarifies this. In addition, you can test it yourself by standing at the boundary between "underground" and "surface", which is at 0 feet depth. The boundary is clear if you remove the dirt walls and look for the change in background, as I've done in this screenshot. (I previously stated you could simply check where the dirt walls stop, this is wrong, they extend several tiles into the underground layer.)

I didn't find any reference for lateral position, but you seem to have that figured out.