Each ship tonnage has an armour factor - this is the number of armour units that are needed for each armour point. The first point is double.
So, with AF 4 (4 units per point), AR 1 costs 8 units, AF2 12 units, and so on.
Each unit is multipled by the cost of it at whatever tech level (plus the base). Also it takes up a tonnage equal to the units times the tons at that tech level.
So, AR 4 for 6 points at Tech 13:
TL 13 is 2 tons per unit, KCr300 per unit (plus a one-off base of KCR200).
AF 4 for AR 6 = 28 units (8+4+4+4+4+4).
28 units takes 56 dtons, and KCr(28*300)+200 = MCr8.6.
So in Excel you would need the following parts:
Number of units:
(AR+1)*AF -- (the AR+1 takes care of the double first point cost).
Dsiplaceemnt:
((AR+1)*AF)*dtons
Cost:
(((AR+1)*AF)*cost)+cost base
If you use lookups for them on a table the formulas will look something like this... (anything in capitals is a variabel you have too supply).For this you need to put the DU/AF table on page 259, and the armour details on page 268 in a column).
Units:
=(AR+1)*lookup(SHIP TONNAGE,du/af table co-ords,AF collumn)
Displacement:
=UNITS RESULT*lookup(ARMOUR TL,armour table co-ords,displacement column)
Cost:
=lookup(ARMOUR TL,armour table co-ords,cost base column)+(UNITS RESULT*lookup(ARMOUR TL,armour table co-ords,cost column))
The table co-ords will be the cell range of the row you are using as a lookup not including any title you put up there (e.g. C6:C18). The xxx column will be the range of the row you want to get the result from in the same table (e.g. E6:E18).
A formula for lookup would look like:
=lookup(a6,c6:c18,e6:e18)
How's that? Any use?
Oh, and the standard deisgns in the book have wildly varying values for the armour weights and costs, so use the ones in the downloadable eratta.
Shane