You need to figure out the reach through of a persons finger through the 1" mesh, and the reach over of the fence. The ANSI/RIA documentation contains this information.
see RIA TR R15.406-2014, [ISO 13857:2008, Table 2] for fence height
see RIA TR R15.406-2014, ISO 13857:2008, 4.2.4.1, Table 4 for reach through for the mesh.