Are you going to use the net for hares? As a 5" mesh is too large for rabbits. I use a 2 1/8th board to give a 41/4 inch mesh and do the net 14 meshes deep+ 2 half selvedge meshes = 15 meshes deep net. 15 x 4.25" = 63.75".
In truth anything around a 60" drop is fine. so if you were using a 4.5" full mesh divide 60 by 4.5 gives you 13.3 full meshes, so 13 would be fine, that would be 12 meshes for the body of the net and 2 half selvedge meshes giving you your 13 meshes deep.
TC
sorry it's just for rabbits when ferreting mate :-). To get the 4.5 inch mesh is that a 2.1/4 inch board with 2