The metric depth to location at any point ‘V’ in plan is the shortest metric path distance from said point to a single universal sample location.

The mean metric depth at any point ‘V’ in plan is the average metric distance from the point to all locations (Hillier, 2009). In an isovist field form it illuminates metric centrality within a configuration.

The Isovist_App determines mean metric depth by averaging all shortest path lengths calculated from point ‘V’ to all successive stochastic global sample locations. In notation form the calculation for mean metric depth is  expressed as:

Where ‘Fi’  is the shortest path distance from location V to a global sample location; and ‘n’ the total number of global sample locations.