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.*