title block

I tried to keep it as close as possible to the standard 180 mm
it can be used on all sizes of paper

with this work i discovered the size of the elements is not exactly
when using landscape A4 i found a printsize of 277x180 in the books
in qet it is 1020 and 640+50(for titleblock)
it gives 3.682310469314079 for horizontal
and 3.833333333333333 for vertical if i am correct. so a square is not nice (oke it is only  1.041013071895425), however
to get it right it needs some calcs
has anybody done this before me?
i have found the following:
size mmvertical mm horizontal          divisions vertical divisions horizontal
A0 821x1159 16x24
A1 574x811 12x16
A2 400x564 8x12
A3 277x390 6x8
A4 180x277 4x6
for all of these i made papersizes as a project, however discovered they are not accurate.
anybody on this?????

For example a symbol like a contact NC or nf is in autocad 15 mm long, in the iso it is 16 and in teq it is 20px
now i am confused
is there anybody out there with accurate measurements of the symbols? in a standard?